Answer:
Area : 14+10+40=64 square unit
Step-by-step explanation:
the area of the top rectangle with sides 2 and 7
A=2*7=14 square unit
the area of the middle rectangle with sides : (7-5)=2 and side (7-2)=5
Area=5*2=10 square unit
the bottom rectangle : sides 10 and 4
Area=10*4=40
add the areas : 14+10+40=64 square unit
PLZ HELP !!!!!! ASAP!!!
Part (a)
BC = opposite side (furthest leg from the reference angle)
AB = adjacent side (closest leg from the reference angle)
AC = hypotenuse (always opposite the 90 degree angle)
=============================================
Part (b)
i. False. Angle B is 90 degrees as shown by the square angle marker.
ii. False. Side AB is opposite angle C. Note how "C" is part of "BC", so that means we cannot have BC be opposite C.
iii. True. Leg AB is the closer leg to angle A. We have "A" in "AB" to see this without having to draw the diagram. Refer to part (a) above.
iv. False. The longest side of any right triangle is always the hypotenuse. The longest side of any triangle is always opposite the largest angle.
==============================================
Part (c)
cos(theta) = adjacent/hypotenuse = AB/AC
tan(theta) = opposite/adjacent = BC/AB
Refer back to part (a) to determine the opposite,adjacent and hypotenuse side lengths.
==============================================
Part (d)
The reference angle has changed, so the opposite and adjacent sides swap. The hypotenuse remains the same regardless of what reference angle you pick.
sin(C) = opposite/hypotenuse = AB/AC
cos(C) = adjacent/hypotenuse = BC/AC
tan(C) = opposite/adjacent = AB/BC
Note the tangent ratio is the reciprocal of what we found back in part (c).
Answer & Step-by-step explanation:
(a)
The hypotenuse is on line CA (the hypotenuse is always opposite the 90° angle (marked by a little square))
The adjacent is on the line BA (adjacent is next to the given angle, but NOT the hypotenuse)
The opposite is on the line CB (this is opposite the given angle)
(b)
i. false (b is a right angle)
ii. false (the side opposite C is BA)
iii. true
iv. false (the side opposite B is the hypotenuse, and the hypotenuse is always the longest side in a triangle)
(c)
cosine ratio: [tex]cos=\frac{adjacent}{hypotenuse}[/tex]
tangent ratio: [tex]tan=\frac{opposite}{adjacent}[/tex]
The cosine and tangent ratios of the given angle:
[tex]cos0=\frac{AB}{CA} \\\\tan0=\frac{CB}{AB}[/tex]
(d)
Remember SOH-CAH-TOA:
Sine=Opposite/Hypotenuse
Cosine=Adjacent/Hypotenuse
Tangent=Opposite/Adjacent
Using the angle C, plug in the appropriate sides:
[tex]sinC=\frac{BA}{CA}\\\\ cosC=\frac{CB}{CA}\\\\ tanC=\frac{BA}{CB}[/tex]
:Done
90 POINTS! HELP ASAP! Using one of the figures below, explain a strategy for calculating the area of the irregular polygon.
Answer:
area of polygon = 88 sq. units
Step-by-step explanation:
lets make it simple, short and accurate.
area of polygon = total area - total area of triangles
total area = 11 * 12 = 132
triangle 1 = 1/2 * 5 * 5 = 12.5
triangle 2 = 1/2 * 3 * 6 = 9
triangle 3 = 1/2 * 3 * 8 = 12
triangle 4 = 1/2 * 3 * 7 = 10.5
total area of triangle = 12.5 + 9 + 12 + 10.5 = 44
area of polygon = 132 - 44 = 88 sq. units
Answer:
The area of the irregular polygon:
88 units²
Step-by-step explanation:
The irregular polygon is insert in a rectangle
The strategy is:
1 - calculate the rectangle total area
2- calculate the area of each right triangle
3.- substracte the total area of the 4 right triangles from the area of the rectángule
then:
1.-
Ar = 12*11 = 132 units²
Ar = rectangle area
2.-
At₁ = (5*5)/2 = 25/2 = 12.5 units²
At₂ = (6*3)/2 = 18/2 = 9 units²
At₃ = (7*3)/2 = 21/2 = 10.5 units²
At₄ = (8*3)/2 = 24/2 = 12 units²
At total = 12.5 + 9 + 10.5 + 12 = 44 units²
At = right triangle areas
3.-
Ap = 132 - 44 = 88 units²
Write and solve an equation to answer the question. How many people must attend the third show so that the average attendance per show is 3000?
Answer:
3250
Step-by-step explanation:
so for the first and 2nd show, the attendance is 2580 and 2920.
The average of both these numbers is 2750
the if the third show had 3000 people, the average attendance would only be 2875.
We need the average number to be 3000.
2750 is 250 less than 3000, so the other number must be 250 more.
3250 is how many people should go to the last show.
=====================================
Explanation:
We have 2580 people attend the first show and 2920 attend the second. So far, that's 2580+2920 = 5500 people. Add on another x people to get 5500+x, which represents the sum of all three days attendance figures. Divide this sum by 3 to get the average attendance
average attendance = (sum of individual attendance values)/(number of days)
average attendance = (5500+x)/3
So that's why (5500+x)/3 goes in the first box. The parenthesis are important to ensure that you divide all of "5500+x" over 3. If you just wrote 5500+x/3, then the computer would think you just want to divide x only over 3.
----------------
We set (5500+x)/3 equal to 3000 as we want the average of the three days to be 3000
(5500+x)/3 = 3000
5500+x = 3*3000
5500+x = 9000
x = 9000-5500
x = 3500
We need 3500 people to show up on day 3 so that the average of all three days is 3000.
3500 goes in the second box.
----------------
Check:
The figures for the three days are 2580, 2920, and 3500
They add to 2580+2920+3500 = 9000
Which divides to 9000/3 = 3000, which is the average we're after. So the answer is confirmed.
describe importance of public participant
Answer:
the main aim of public participant is to encourage the public to have a meaningful input into the decision making process.
Plz Help I Will Mark Brainliest If Right f(x) = x^2 + 3 A). y > -3 B). All real numbers C). y ≥ 3 D). y ≤ 3
Answer:
C) y ≥ 3
Step-by-step explanation:
The answer choices suggest that you're interested in the range of the function. x^2 cannot be negative, so its value will be 0 or greater. Adding 3 to x^2 ensures that the value of f(x) will be 3 or greater.
y ≥ 3 . . . . matches C
A physiological psychologist has performed an experiment to determine if a particular drug, smartozine, affects maze learning in rats. Three groups of 8 rats each are injected with one of three different doses of smartozine, while a fourth group of 6 rats is injected with a saline solution as a control. After the injection, rats in all four groups are timed in how long it takes them to learn to traverse a maze. The results of the experiment are presented below. Did smartozine affect how quickly the rats learned the maze. Use a level of significance of.05 SSB 610 SSW = 1742 What is the critical value of F for this situation?
Answer:
The critical value of F for this situation is 2.975.
Step-by-step explanation:
A test is being performed to determine if a particular drug, smartozine, affects maze learning in rats.
The groups are divided as follows:
Three groups of 8 rats each are injected with one of three different doses of smartozine.The fourth group of 6 rats is injected with a saline solution as a control.So, there were in total k = 4 groups with n = 30 rats.
The significance level of the test is, α = 0.05.
Compute the critical value of F as follows:
[tex]F_{\alpha, (k-1, n-k)}=F_{0.05, (4-1, 30-4)}=F_{0.05, (3,26)}=2.975[/tex]
*Use the F-table.
Thus, the critical value of F for this situation is 2.975.
The critical value of F for this situation has been 2.975.
The F value has been the statistical factor that has been used for the determination of the significance of the test.
The high F value has been the representation of the rejected null hypothesis, while the low F value represents the accepted hypothesis. The study that has been performed with the rats has:
Number of groups of rats = k = 4
Total number of rats = n = 30
The 0.05 significance test has been performed, thus the value of α has been 0.05.
The value of F can be given as:
Critical value = [tex]\rm F_\alpha_\;_,(_k_-_1,_n_-_k_)[/tex]
Substituting the values:
Critical value = [tex]\rm F_0._0_5,_(_4_-_1,_3_0_-_4_)[/tex]
Critical value = 2.975
Thus, the critical value of F for this situation has been 2.975.
For more information about the F value, refer to the link:
https://brainly.com/question/11566053
9. You run a business making birdhouses. You spend $600 to start your business, and it costs you $5.00
to make each birdhouse.
# of birdhouses
1
2
3
4
5
6
7
Total cost to build
Answer:
$635
Step-by-step explanation:
$5x7 birdhouses=$35want
So, $35+$600=$635 total!
I hope this helps you!
Multiplication is the process of multiplying. The cost of building 7 birdhouses will be $635.
What is multiplication?Multiplication is the process of multiplying, therefore, adding a number to itself for the number of times stated. For example, 3 × 4 means 3 is added to itself 4 times, and vice versa for the other number.
The cost of the birdhouse is the sum of the fixed cost, which is the setup cost of the business of $600, and the variable cost is the cost that is needed to make a single house, therefore, $5.
Now, the total cost of making n number of houses will be,
Cost of making n house = Fixed cost + variable cost
= $600 + $5(n)
Further, the table can be filled using the above formula by substituting the value of n for the number of houses. Therefore,
Number of bird houses Total cost to build
1 $600+$5(1) = $605
2 $600+$5(2) = $610
3 $600+$5(3) = $615
4 $600+$5(4) = $620
5 $600+$5(5) = $625
6 $600+$5(6) = $630
7 $600+$5(7) = $635
Hence, the cost of building 7 birdhouses will be $635.
Learn more about Multiplication here:
https://brainly.com/question/14059007
#SPJ2
What is the center of the circle with the equation (x+4)2 + (y - 2)2 = 16?
Answer:
The center of the circle is
( - 4 , 2)Step-by-step explanation:
Equation of a circle is given by
(x - h)² + ( y - k)² = r²where r is the radius
(h, k) is the center of the circle
The center of a circle is given by
( - h , - k)
From the question equation of the circle is
( x + 4)² + ( y - 2)² = 16
Comparing with the general equation above
( h , k) = ( 4 , - 2)
The center of the circle is
( - h , - k) = ( - 4 , -(-2))
We have the final answer as
( - 4 , 2)Hope this helps you
What is the difference between a matrix and a determinant?
Answer:
Step-by-step explanation:
A matrix is a set of numbers organized in rows and columns to represent the variables in a situation, and the determinant is used to find the inverse of a matrix which helps you solve for different variable values.
Answer: A matrix or matrices is a rectangular grid of numbers or symbols that is represented in a row and column format. A determinant is a component of a square matrix and it cannot be found in any other type of matrix. ... A determinant is a number that is associated with a square matrix.
Step-by-step explanation:
HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
6) C
7) A
8) D
9) B
Step-by-step explanation:
when the sign is < or > then the point is clear point(white)
when the sign is ≤ or ≥ then the point is solid ( black)
6) 4y+3≤y+6
4y-y≤6-3
3y≤3
y≤3/3
y≤1 (C)
7) -2y>2 ( wen sign is negative you flip the sign from> to <)
y<-2/2
y<-1 (A)
---------------------------------------------------------------------------------------
8) y/3<-1 ⇒ y<-3 the sign is < means it is clear and on -3 (D)
--------------------------------------------------------------------------------------
9) 3y≤2y+3
3y-2y≤3
y≤3 ( B)
State if the triangles are similar. If so, how do you know they are similar and complete the similarity statement. Triangle LKJ≈____
Answer: C) similar, SAS similarity, triangle LQR
==============================================
Explanation:
The vertical angles KLJ and QLR are congruent. This forms the "A" in "SAS". The angles in question are between the marked sides.
KL = 18 is twice that of QL = 9, or put another way, KL/QL = 18/9 = 2. The ratio of the sides is 2. Also, JL/RL = 16/8 = 2 is the same ratio. Because both pairs of sides have the same ratio, the sides are in proportion. This helps form the two "S" letters of "SAS".
The original triangle has LKJ mentioned at the top. Note the order as its important. We start with L and move to K, so LK is the first segment mentioned. LK = 18 pairs up with LQ = 9, meaning that LQ must be the first segment mentioned of the answer triangle. Therefore LQR is the correct letter sequence if we start with point L. Writing QLR is not correct because Q is the first letter here but Q does not pair up with L.
Can someone pls help and explain it
Answer:
(7,-4) ; 12
Step-by-step explanation:
Basically, three corners of a rectangle are already on the graph. If you put a dot at (7,-4), that is the last corner(vertex) that finishes the rectangle
Then to find base of the rectangle, you find the length of the longer side, (the distance between the x coordinates). So you would subtract -5 from 7 and get 12, and 12 is the length of your base.
Can you help me find all the seventh roots of unity? what do they look like graphed?
Answer:
There are seven seventh roots of unity, e2πki7 , all on the unit circle, r=1 above.
The first one is at θ=2π7=360∘7=5137 ∘ , and there are others at 4π7,6π7,8π7,10π7,12π7 and of course at 0 radians, i.e. unity itself.
How to find?
There are 4 fourth roots of unity and they are 1, i,−1 and−i
Each of the roots of unity can be found by changing the value of k k k in the expression e 2 k π i / n e^{2k\pi i/n} e2kπi/n. By Euler's formula, e 2 π i = cos ( 2 π ) + i sin ( 2 π ) = 1.
The sum of three consecutive multiples of 7 is 777 find these multiples
let the consecutive multiples be 7(n-1) , 7n and 7(n+1)
so 7(n-1)+7n+7(n+1)=777
or 3n=111,
n=37
252,259,266
[tex]7n+7n+7+7n+14=777\\21n=756\\n=36\\\\7n=252\\7n+7=259\\7n+14=266[/tex]
252,259,266
Type the correct answer in the box. Use numerals instead of words. If necessary, use / for the fraction bar.
Use digits to write the value of the 6 in this number.
672,180
Six hundred thousand
Hope it helps :)
a businessman bought three machines at rs 5400 each and spent 4000 on rearing and sold the machines for Rs Rs 7000 each, how much profit didi he make?
Answer:
[tex] \boxed{Rs \: 800}[/tex]Step-by-step explanation:
Cost price of three machines with repairment charge ( CP ) = 5400 × 3 + 4000
= Rs 20200
Selling price of 1 machine = Rs 7000
Selling price of 3 machines ( S.P )= Rs 7000 × 3
= Rs 21000
Since , SP > CP , he made a profit
Profit = SP - CP
= Rs 21000 - Rs 20200
= Rs 800
--------------------------------------------------------------
Further more explanation
Profit and loss
In any business , owners have intension to have profit by selling articles. The price at which an article is purchased is called it's Cost price ( C.P ) and the price at which it is sold is called Selling price ( S.P ).
If the selling price is less than cost price of an article then there is a loss.
[tex] \mathrm{Loss \: = \: Cost \: Price \: (C.P) - Selling \: Price \: (S.P)}[/tex]
If the selling price is more than cost price of an article then there is a profit ( gain )
[tex] \mathrm{Profit = Selling \: Price \: (S.P) - Cost \: Price \: (C.P)}[/tex]
So, If S.P > C.P, there is profit in dealing.
If C.P > SP , there is loss in dealing.
Hope I helped!
Best regards!!
Two numbers are in ratio 3 by 2 and their difference is 5 find numbers
Answer:
The first number is 15, the second number is 10Step-by-step explanation:
a:b = 3:2 ⇒ a = 3x and b = 2x
a - b = 5
3x - 2x = 5
x = 5
a = 3•5 = 15
b = 2•5 = 10
Evaluate. Write in standard form.
Answer:
-i
Step-by-step explanation:
(-i)^0 = 1
(-i)^1 = -i
(-i)^2 = -1
(-i)^3 = -i
(-i)^4 = 1
(-i)^5 = -i
etc.
From this pattern, you see that when the exponent is a multiple of 4, you get 1. When the exponent is a multiple of 4 plus 1, you get -i, etc.
213 = 4 * 53 + 1
213 is 1 more than a multiple of 4.
(-i)^213 = (-i)^1 = -i
La madre de rosita se ha comprado una mascarilla por un valor de 1 25 dolares al mismo tiempo se ha comprado un paquete de jabones de 2 00 dolares y luego compra un gel de alcohol en 3 00 dolares después de pagar le queda 7 65 dolares que debemos saber que tengo que hacer para obtener el resultaron
Answer:
La cantidad inicial que tenía la madre de Rosita antes, comprando los artículos es de $13.90
Step-by-step explanation:
La información dada son;
El valor de la máscara = $ 1.25
El valor del paquete de jabones = $ 2.00
El valor del gel de alcohol = $ 3.00
La cantidad que le quedaba después de pagar = $ 7.65
Por lo tanto, tenemos;
La cantidad inicial que tenía la madre de Rosita antes, comprando los artículos = La cantidad que le quedaba después de pagar + El valor del gel de alcohol + El valor del paquete de jabones + El valor de la mascarilla
Por lo tanto;
La cantidad inicial que tenía la madre de Rosita antes, comprando los artículos = $ 7.65 + $ 3.00 + $ 2.00 + $ 1.25 = $ 13.90.
Ahmad has some files.
زرا
He gave
of the files and had 14 files left.
5
How many files did he have at first?
Step-by-step explanation:
why did u add the 5 in the question?.
HELP PLEASE ASAP I REALLY DONT KNOW HOW TO DO THIS
What is the slope of a line perpendicular to the line containing the points $(-1,2)$ and $(1,-2)$? Express your answer as a common fraction. Enter your answer
Answer:
[tex]\frac{1}{2}[/tex]
Step-by-step explanation:
Calculate the slope of the line m using the slope formula
m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]
with (x₁, y₁ ) = (- 1, 2) and (x₂, y₂ ) = (1, - 2)
m = [tex]\frac{-2-2}{1+1}[/tex] = [tex]\frac{-4}{2}[/tex] = - 2
Given a line with slope m then the slope of a line perpendicular to it is
[tex]m_{perpendicular}[/tex] = - [tex]\frac{1}{m}[/tex] = - [tex]\frac{1}{-2}[/tex] = [tex]\frac{1}{2}[/tex]
plz help asap i have limited time i will give brainliest
Answer:
358
Step-by-step explanation:
In 1995, the boys were 50 %
Take the number of people at the convention in 1995 ( 716)
and multiply by 50%
716 * 50%
716 * .50
358
Answer:
b. 358
Step-by-step explanation:
First, find what percentage of attendees were boys in 1995:
By reading the graph, we can see 50% were boys.
In the table, we can see that there were 716 attendees in 1995.
To find how many boys attended in 1995, find 50% of 716.
716(0.5) = 358
hi there can you please help me
[tex]t = \sqrt{ \frac{ab - s}{r + ak} } [/tex]
[tex]t=\sqrt{\dfrac{ab-s}{r+ak}}\\\\t^2=\dfrac{ab-s}{r+ak}\\\\rt^2+akt^2=ab-s\\\\akt^2-ab=-rt^2-s\\\\a(kt^2-b)=-(rt^2+s)\\\\a=-\dfrac{rt^2+s}{kt^2-b}\\\\a=-\dfrac{rt^2+s}{-(b-kt^2)}\\\\a=\dfrac{rt^2+s}{b-kt^2}[/tex]
Jess receives a $15000 salary for working as an engineer. If Jess has to spend $6000 of her salary on expenses each year, then what percent of Jess's money does she have to spend? Round your answer to the nearest whole number if necessary.
Answer:
Jess will have to spend 40% of her salary
Step-by-step explanation:
Jess salary = $15,000
Jess expenses = $6,000
what percent of Jess's money does she have to spend
Percentage of Jess expenses = Jess expenses / Total salary × 100
= 6,000 / 15,000 × 100
= 0.4 × 100
= 40%
Jess will have to spend 40% of her salary
PLEASE HELP FOR REAL
In exercises 22 24 , describe how the change affects the surface area of the right prism or right cylinder .
Answer:
22. The surface area is 1/9 of its original value
24. The surface area is 120 m^2 less than its original value.
Step-by-step explanation:
22. For similar figures, the surface area is proportional to the square of the linear dimension scale factor. Multiplying all linear dimensions by 1/3 will result in reducing the surface area to (1/3)^2 = 1/9 of its original value.
__
24. As above, the scaled base surface area will be (1/4)^2 = 1/16 of its original value. Since one dimension of the lateral area is multiplied by 4 and the other dimension is multiplied by 1/4, the net effect on that area is multiplication by (1/4)(4) = 1. That is, the lateral area will remain unchanged.
The overall surface area will be reduced by 15/16 of the area of the bases. The area of the bases is (2)(1/2)(8 m)(16 m) = 128 m^2. The changed figure will have a surface area that is 120 m^2 smaller.
what is the value of this expression when g= -3.5?
8-|2g-5|
a. 20
b. 10
c. 6
d. -4
Answer:
d. -4
Step-by-step explanation:
Let's plug in g
8 - |2(-3.5) - 5|
8 - |-7-5|
8 - |-12|
The absolute value is always positive of any number,
8 - 12
= -4
Answer:
D. -4
Step-by-step explanation:
We are given this expression:
[tex]8-|2g-5|[/tex]
and asked to evaluate when g= -3.5 Therefore, we must substitute -3.5 in for g.
[tex]8-|2(-3.5)-5|[/tex]
First, multiply 2 and -3.5
2 * -3.5 = -7
[tex]8-|-7-5|[/tex]
Next, subtract 5 from -7.
-7-5= -12
[tex]8-|-12|[/tex]
Next, evaluate the absolute value of -12. The absolute value is how far away a number is from 0, and it is always positive. The absolute value of -12 is 12.
[tex]8-12[/tex]
Subtract 12 from 8.
[tex]-4[/tex]
The value of the expression is -4 and D is the correct answer.
Please answer this question now
Answer:
11 yd
Step-by-step explanation:
To find the volume of a rectangular prism, we multiply the width, length and height.
We already know the length, 18, and the height, 11, and the volume, 2178, so we can easily solve for y.
[tex]18\cdot y\cdot11=2178\\192y=2178\\y = 11[/tex]
Hope this helped!
The size of a television screen is given as 95 cm, correct to the nearest 5 cm.
Write down the upper bound of the size of the television screen.
Answer:
The upper bound is 97.5 cm
Step-by-step explanation:
The upper bound is given as the value that is larger than or equal to all values in a data set, for example, in the data set, {3, 6, 16, 23, 25}, an upper bound is 25, however, where the accuracy of the data is given, the upper bound can be found by the following relation
Where the number is given to the nearest 100, add and subtract half of hundred to obtain the upper bound and lower bound respectively
For the question, given that the size of the television is given as 95 cm, correct to the nearest 5 cm, we add add half of 5 cm to get the upper bound as follows;
Upper bound = 95 cm + 5/2 cm = 97.5 cm
The upper bound = 97.5 cm.
What is a21 of the arithmetic sequence for which a7=−19 and a10=−28? A. -35 B. 35 C. -58 D. -61
Answer:
a21 = -61
Step-by-step explanation:
[tex]a_{n}=a_{1}+(n-1)d[/tex]
[tex]-19=a_{1}+(7-1)d[/tex]
[tex]-28=a_{1}+(10-1)d[/tex] (subtract to eliminate a₁)
9 = -3d
d = -3
-19 = a₁ + (6)(-3)
-1 = a
a21 = -1 + (21 - 1)(-3)
= -61
Answer:
-61 (Answer D)
Step-by-step explanation:
The general formula for an arithmetic sequence with common difference d and first term a(1) is
a(n) = a(1) + d(n - 1)
Therefore, a(7) = -19 = a(1) + d(7 - 1), or a(7) = a(1) + d(6) = -19
and a(10) = a(1) + d(10 - 1) = -28, or a(1) + d(10 - 1) = -28
Solving the first equation a(1) + d(6) = -19 for a(1) yields a(1) = -19 - 6d. We substitute this result for a(1) in the second equation:
-19 - 6d + 9d = -28. Grouping like terms together, we get:
3d = -9, and so d = -3.
Going back to an earlier result: a(1) = -19 - 6d.
Here, a(1) = -19 - 6(-3), or a(1) = -1.
Then the formula specifically for this case is a(n) = -1 - 3(n - 1)
and so a(21) = -1 - 3(20) = -61 (Answer D)
Factor 4 out of 4x + 12.
Answer:
4(x + 3)
Step-by-step explanation:
So, to solve these questions is pretty simple.
4 times what equals 4x, and 4 times what equals 12?
Well,
4 times x = 4x, and 4 times 3 = 12.
soo.
4(x + 3)
Answer:
4x+12 factor 4 out of the equation
4(x+3)19) : -7x=5.6⇒ x=-5.6/-7
x=5.6/7=0.8x/8- 5/2=5/2 common factor
(x-20)/8 =5/2
2(x-20)=40
2x-40=40
2x=80
x=80/2=40