Answer:
775
Step-by-step explanation:
We are given two equations in which we can perform systems of equations by putting these two equations on top of each other then solving for one variable:
x+y=15
x-y=25
Here, we can cancel out the y variable and get:
2x=40
x=20
Then we can put the x variable into any of the equations to solve for y (in this case I will use the equation x+y=15 so 20+y=15
y=-5
Now, we can solve by plugging both variables into 2x^2 - y^2 :
2(20)^2 - (-5)^2
800-25 = 775
I hope this helps!
Answer:
775
Step-by-step explanation:
Hi there!
We are given the following system of equations:
x+y=15
x-y=25
and we need to find the value of 2x²-y²
First, let's find the value of x and y
Let's add the 2 equations together to clear y and solve for x (y-y=0)
2x=40
divide both sides by 2
x=20
Now substitute 20 as x into either one of the equations to solve for y
To do x-y=25 for instance,
20-y=25
subtract 20 from both sides
-y=5
multiply both sides by -1
y=-5
Now we know that x=20 and y=-5
Substitute those values into the expression (remember: y² is equal to y×y, or (y)²)
2(20)²-(-5)²
Raise to the second power
2(400)-(25)
multiply and open parenthesis
800-25
subtract
775
Hope this helps!
PLEASE HELP WILL MARK BRAINLIEST!!!! You work for a consumer advocate agency and want to find the mean repair
cost of a washing machine. As part of your study, you randomly select 40
repair costs and find the mean to be $120.00. The sample standard deviation
is $17.50. The 99% confidence interval for the population mean repair cost is? A.(112.86, 127.14) B.(114.58, 125.42) C. (115.43, 124.57) D. (111.57, 128.43)
Answer:
The correct answer is - A.(112.86, 127.14)
Step-by-step explanation:
Given:
mean = $120
sd = $17.50
n = 40
Solution:
Confidence interval for a populationcan be express as mean +/- margin of error (E)
degree of freedom = n-1 = 40-1 = 39
confidence level (C) = 99% = 0.01
significance level = 1 - C = 1 - 0.01 = 0.99 = 99%
by margin of error E = t×sd/√n = 2.58*17.50/√40
= 2.58*2.76
= 7.138 or 7.14
then the lower limit of mean = mean - E = 120 - 7.14 = $112.86
and, the upper limit of population mean = mean + E = 120 + 7.14 = $127.14
8x square + 1 + 3square - 2
Answer:
8x^2-1+3^2
Step-by-step explanation:
if an object is bought for rupees 90 and then sold for a loss of 15% how much was it sold for
Answer:
76.50
Step-by-step explanation:
We are given the fact that you bought an object for 90 dollars, and in which you sold said object for a loss of 15%, we are then asked how much would that object be sold for.
To find the answer, we need to subtract the original amount by the percent loss, so :
90 - 15%
15% of 90 is 13.5, therefore :
90 - 13.5
76.5
Which term can be used in the blank of 36x3−22x2−__ so the greatest common factor of the resulting polynomial is 2x? Select two options.
2
4xy
12x
24
44y
Answer:
[tex]4xy[/tex][tex]12x[/tex]-------------
[tex]36x^3,\:22x^2,\:4xy[/tex]
Factor 36x³
[tex]2\cdot \:2\cdot \:3\cdot \:3\cdot \:x\cdot \:x\cdot \:x\\[/tex]Factor 22x²
[tex]11\cdot \:2\cdot \:x\cdot \:x[/tex]Factor 4xy
[tex]2\cdot \:2\cdot \:x\cdot \:y[/tex]Common factor
[tex]2x[/tex]---------------------
[tex]36x^3-22x^2-12x[/tex]
Factor 36x³
[tex]2\cdot \:2\cdot \:3\cdot \:3\cdot \:x\cdot \:x\cdot \:x[/tex]Factor 22x²
[tex]11\cdot \:2\cdot \:x\cdot \:x[/tex]Factor 12x
[tex]2\cdot \:2\cdot \:3\cdot \:x[/tex]Common factor
[tex]2x[/tex]OAmalOHopeO
Helpless! I need help.
Answer:
0
Step-by-step explanation:
r=5
So
=5⁴-5(5)³-4(5)²+5(5)+75
=5⁴-5(125)-4(25)+5(5)+75
=625-625-100+25+75
=0
Please explain, thank you
Answer:
C. 2.
Step-by-step explanation:
The graph descends from the left so the coefficient of the leading term is negative. It is also a cubic equation with zeros of -20, about 6.5 and about 13. so we can write the equation as below. The last 2 values can only be guessed because the x axis only shows values which are multiples of 5.
f(x) = a(x + 20)(x - 6.5)(x - 13) where a is a negative constant.
(This is only an approximation).
By the Remainder theorem, when the expression is divided by (x + 10):
f(-10) = -20 so we have
-20 = a (-10 + 20)(-10-6.5)(-10 - 13)
(10)(-16.5)(-23)a = -20
a = -20 / (10)(-16.5)(-23)
a = -0.0053
When the equation is divided by (x - 10) then f(10) is the remainder so substituting we have as the remainder:
-0.0053(10+20)(10-6.5)(10 -13)
-0.0053 * 30 * 3.5 * -3
= 1.7 approximately.
Looks like the answer is 2.
Draw the graphs of the pair of linear equations : x + 2y = 5 and 2x - 3y = -4 Also find the points where the lines meet the x - axis .
Answer:
(1, 2)
Step-by-step explanation:
Given the equation of the lines x + 2y = 5 and 2x - 3y = -4
First we need to make x the subject of the formulas
For x+2y = 5
x = 5 - 2y ... 1
For 2x - 3y = -4
2x = -4+3y
x = (-4+3y)/2 ... 2
Equate 1 and 2
5 - 2y = (-4+3y)/2
2(5-2y) = -4+3y
10 - 4y = -4+3y
-4 -3y = -4-10
-7y = -14
y = 14/7
y = 2
Substitute y = 2 into 1
x = 5 = 2y
x = 5 - 2(2)
x = 5 - 4
x = 1
Hence the point where the lines meet will be at (1, 2)
-5x(x+1)
simplify the answer
Answer:
[tex]-5x^2-5x[/tex]
Step-by-step explanation:
[tex]-5x\left(x+1\right)\\\\-5x\left(x+1\right)=-5xx-5x\cdot \:1\\\\=-5xx-5x\cdot \:1\\\\=-5x^2-5x[/tex]
Answer:
-5x^2 -5x
Step-by-step explanation:
-5x(x+1)
Distribute
-5x*x +-5x*1
-5x^2 -5x
The tens digits of a certain two-digit number is 1/3 of the units digit. When the digits are reversed, the new number exceed twice the original number by 2 more than the sum of the digits. Find the original number.
Answer:
The orginal number is 26.
Step-by-step explanation:
So the units digit can be 3 6 or 9
The tens digit can be 1 2 or 3
So the original number can be 13
31 = 2*13+ (1+3) + 2
31 =? 26 + 4 + 2
This doesn't work. The right side is 32
26
62 = 2*26 + 8 + 2
62 = 52 + 8 + 2
This is your answer.
3 and 9 won't work because 39 is odd and so is 93. The result has to be even.
what is the lowest common denominator of 4 7 5 2 and 1
Answer:
140
Step-by-step explanation:
Lowest common denominator 4 , 7 ,5 , 2 and 1
= 4 * 7 * 5
= 140
Answer:
1
Step-by-step explanation:
Since usually common denominator is usually used with fractions (in this case), we can find out it's one because of how no numbers (except for 2 and 4) go into each other without a remainder except for one, so one would be the correct answer
Suppose you buy 6 cans of peaches at $1.10 each, 5 cans of corn for $.89 each, and 3 boxes of breakfast cereal at $3.52 each. a. Write three expressions; one each that shows how to determine the total spent on peaches,
corn and breakfast cereal. (3 pts)
Si yo tendria que sumar esos numeros daria: 21.61
porque, 6x1.10= 6.60
5x0.89= 4.45
y las tres cajas de cereal 3x3.52
the perimeter of equilateral triangle is 21m. Find the area. Using Heron's Formula
plzzz answer fast i will mark brainliest.
Answer:
A ≈ 21.22 m²
Step-by-step explanation:
The area (A) of a triangle using Heron's formula is
A = [tex]\sqrt{s(s-a)(s-b)(s-c)}[/tex]
where s is the semi perimeter and a, b, c the sides of the triangle.
Here the perimeter of the equilateral triangle is 21 m , then
a = b = c = 21 ÷ 3 = 7 m
s = 21 ÷ 2 = 10.5
Then
A = [tex]\sqrt{10.5(10.5-7)(10.5-7)(10.5-7)}[/tex]
= [tex]\sqrt{10.5(3.5)(3.5)(3.5)}[/tex]
= [tex]\sqrt{450.1875}[/tex]
≈ 21.22 m² ( to 2 dec. places )
What is the slope of the line that passes through the points (-20, 18) and (30, 14)?
Answer:
-2/25
Step-by-step explanation:
Use the slope formula: rise/run to find the slope
Answer:
slope = - [tex]\frac{2}{25}[/tex]
Step-by-step explanation:
Calculate the slope m using the slope formula
m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]
with (x₁, y₁ ) = (- 20, 18) and (x₂, y₂ ) = (30, 14)
m = [tex]\frac{14-18}{30-(-20)}[/tex] = [tex]\frac{-4}{30+20}[/tex] = [tex]\frac{-4}{50}[/tex] = - [tex]\frac{2}{25}[/tex]
A cylindrical vase has a volume of 192.5 cubic centimeters. The height of this vase is 5 centimeters. The formula for the volume of the cylinder is πr^2h where r is the radius and h is the height of the vase. Find the radius of this vase.(Given that π ≈ 22 / 7 )
Answer:
3.5 cm
Step-by-step explanation:
v = πr²h
r = radius
π = 22/7
h = height
192.5 = 22/7 x 5 x r²
divide both sides of the equation by (7/22 x 1/5)
192.5 x 7/22 x 1/5 = r²
r² = 12.25
find the square root of both sides
r = 3.5cm
Find the missing number.
____ × 7 = 91
please help me
Answer: 13
Step-by-step explanation:
Take 7 to the other side and divide 91 by 7, the answer will be 13.
Geometry, please answer question ASAP
Answer:
D
Step-by-step explanation:
The median goes from the vertex to the midpoint of the opposite side, so
LN = NM , that is
3x - 7 = 5 ( add 7 to both sides )
3x = 12 ( divide both sides by 3 )
x = 4
Then
KL = 2x + 3 = 2(4) + 3 = 8 + 3 = 11 → D
Two similar pyramids have similarity ratio 3:5 find the ratio of the areas and the ratio of the volume
Answer:
Area=9:25 Volume=81:625
Step-by-step explanation:
Should be squared, might be wrong.
Identify one similarity and one difference between the graph of 2x + 4 and the graph of y= -1/2x + 4
Answer:
Similarity: Both graphs have same y-intercepts.
Difference: Graph 2x + 4 has a slope of 2 while the graphic -½x + 4 has a slope of -½
Step-by-step explanation:
[tex]{ \sf{y = mx + b}}[/tex]
m is the slope
b is the y-intercept
Help please URGRENTTTTT
The graph below shows a company’s profit f(x), in dollars, depending on the price of pens x in dollars sold by the company:
Part A: what do the x-intercepts and maximum value of the graph represent? What are the intervals where the function increasing and decreasing, and what do they represent about the dale and profit?
Part B: what is an approximate average rate of change of the graph from x=3 to x=5, and what does this rate represent?
Part C: describe the constraints of the domain
Answer:
Part AThe x-intercepts are reflecting zero-profit: (0, 0) and (6, 0).
The maximum value of the graph is at vertex (3, 120): maximum profit when the price is $3.
The function is increasing until the vertex, between x-value of 0 to 3 and is decreasing once it reached the vertex, between x-value of 3 to 6.
In the first interval the sale and profit increases, in the second interval the sale and profit decreases.
Part BAverage rate of change from x = 3 to x = 5 is:
(f(5) - f(3))/(5 - 3) = (60 - 120)/2 = -30This represents the profit drop of $30 per $1 price increase when price changes from $3 to $5.
Part CThe domain is representing the price. It should be profitable so it is between $0 and $6.With one method of a procedure called acceptance sampling, a sample of items is randomly selected without replacement and the entire batch is rejected if there is at least one defective unit. The ABCD Electronics Company has just manufactured 7000 write-rewrite CDs, and 180 are defective. If 6 of these CDs are randomly selected and tested, what is the probability that the entire batch will be rejected
Answer:
[tex]P = 0.1447[/tex]
Step-by-step explanation:
Given
[tex]n = 7000[/tex] -- total
[tex]d = 180[/tex] --- defective
[tex]r = 6[/tex] --- selected
Required
The probability of rejecting the batch
This means that at least one of the selected piece is defected.
So, we first calculate the probability that all the selected piece are accepted.
So, we have:
[tex]Pr = \frac{7000 - 180}{7000} * \frac{6999 - 180}{6999}* \frac{6998 - 180}{6998}* \frac{6997 - 180}{6997}* \frac{6996 - 180}{6996}* \frac{6995 - 180}{6995}[/tex]
The denominator decreases by 1 because it is a probability without replacement; 180 is subtracted from the numerator to represent the number of non-defective CDs
So, we have:
[tex]Pr = \frac{6820}{7000} * \frac{6819}{6999}* \frac{6818}{6998}* \frac{6817}{6997}* \frac{6816}{6996}* \frac{6815}{6995}[/tex]
[tex]Pr = 0.8553[/tex]
Using the complement rule, the probability that the batch will be rejected is:
[tex]P = 1 - 0.8553[/tex]
[tex]P = 0.1447[/tex]
toán 9 nha mọi người
Answer:
Thamkhao
Step-by-step explanation:
A line with slope 3 intersects a line with slope 5 at the point (10, 15). What is the distance between the x-intercepts of these two lines?
Answer:
2
y = 3x-15
y=5x-35
x1=5
x2=7
distance between = 7-5 = 2
Step-by-step explanation:
Value of the boat after 3 years?
after each year it's 83% of it's value from last year (100%-17%=83%)
the function in 19000 * (0.83) ^x
3 will be filled in for x
19000 * (0.83) ^3= 10863.953
$10863.95
Answer:
$10,863.95
Step-by-step explanation:
y = 19,000[tex](.83)^{t}[/tex]
y = 19,000[tex](.83)^{3}[/tex]
y =$10,863.95
Write the quadratic expressions in the numerator and the
denominator in factored form
4x^2-14x+6/
X^3-7x^2+12x
I have to give 2 Ans form my question so sorry
I need help pls pls pls pls
Answer:
1. -18x+6
multiply everything inside with the number outside the bracket
2. -18x-6
same as number one
3. 18x-12
same as number one
4. -18x-6
same as number one
for 5 I can't see it well but it should be similar
you just need to substitute what's outside the bracket to what Is inside the bracket
Answer: -6 (3x+1)
Step-by-step explanation:
Factor the polynomial -18x-6−18x−6 by it's GCF: -6−6
Geometry, please answer question ASAP
BECAUSE ACCORDING TO THE PERIMETER (TRIANGLE ) FORMULA = B * H / 2.
B = BASE.
H = HEIGHT.
THE HEIGHT IS A VARIABLE VLAUE NEEDED IN ORDER TO ONTINUE TO SOLVE AND EVENTUALLY LEADING TO THE ANSWER (TRIANGLE PERIMETER.
rational or irrational? and why
Answer:
rational, simplified number is -0.5
Step-by-step explanation:
(see screenshot)
Can someone please check my answers and help/explain #4
Answer:
(0,8)
Step-by-step explanation:
To get the y-intercept put all x values equal to 0 (because we want to see where y lies on the graph when x is zero.
y=2^0+3
y=2^3
y=8
The y-intercept is (0,8)
As for the rest of the answers.....
1)A) 2[tex]\sqrt{12}[/tex]-5[tex]\sqrt{3}[/tex] = 4[tex]\sqrt{3}[/tex]-5[tex]\sqrt{3}[/tex] so the final answer is -[tex]\sqrt{3}[/tex]
1B) the problem is (3-[tex]\sqrt{7}[/tex])(3+[tex]\sqrt{7}[/tex]) a quick formula to help you solve this type of problem is (a-b)(a+b)= a^2-b^2 so you transform the question to 3^2-[tex]\sqrt{7}[/tex] ^2
to get 9-7 which is 3 therefore the final answer is 3
2) when you transform a function from y=x^2-3 to y=x^2+1 the graph moves 4 units up. So the final answer is b)4 units up
Question 3a and 3b are correct
The surface area of a cylinder is given by the formula
S = 30πr + 2πr2
How many times greater is this compared to a circle with A = πr2
Answer:
[tex] x = \frac {30}{r} + 2 [/tex]
Step-by-step explanation:
Given the following data;
S.A of cylinder = 30πr + 2πr²Area of circle = πr²To find how many times greater is the S.A compared to the area, we would have to divide the surface area (S.A) of the cylinder by the area of circle.
Let the unknown variable be x.
[tex] x = \frac {30 \pi r + 2 \pi r^{2}}{\pi r^{2}} [/tex]
Factorizing the numerator, we have;
[tex] x = \frac {\pi r(30 + 2r)}{\pi r^{2}} [/tex]
Dividing both sides by πr, we have;
[tex] x = \frac {30 + 2r}{r} [/tex]
Simplifying further, we would have;
[tex] x = \frac {30}{r} + 2 [/tex]
The table shows values for a quadratie function
What is the average rate of change for this function for the interval from 1
Please see
Pic
Answer:
B
Step-by-step explanation:
The average rate of change of f(x) in the closed interval [ a, b ] is
[tex]\frac{f(b)-f(a)}{b-a}[/tex]
Here [ a, b ] = [ 1, 3 ] , then
f(3) = 18 ← value of y when x = 3
f(1) = 2 ← value of y when x = 1
Then
average rate of change = [tex]\frac{18-2}{3-1}[/tex] = [tex]\frac{16}{2}[/tex] = 8 → B
