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Answer:
(x, y) = (3, 12)
Step-by-step explanation:
The first step in any problem solving is to look at the problem. Here, we see that the first equation can be reduced to standard form by dividing it by 2. This would give both terms a coefficient of 1.
We see that the second equation already has a variable with a coefficient of 1.
When solving a system by substitution, it can save some effort if you start by finding a variable with a coefficient of 1 or -1. Since we see that in the second equation, we choose to solve the second equation for y:
y = 4x . . . . . . . add 4x to both sides of the second equation
Now, we have an expression for y that we can substitute into the first equation.
2x +2(4x) = 30 . . . . substitute for y
10x = 30 . . . . . . . . simplify
x = 3 . . . . . . . . . . divde by 10
y = 4(3) = 12 . . . . . find y using y=4x
The solution is (x, y) = (3, 12).
__
Additional comment
I doesn't matter what variable gets substituted. The purpose of the exercise is to reduce the number of variables in the equation. Here, we start with an equation that has 2 variables. Substituting for one of them gives an equation with only one variable, a lot easier to solve.
You don't have to find an expression for the "bare" variable. We could solve the second equation for 2x, for example: 2x = y/2, then substitute for 2x in the first equation: y/2 +2y = 30 ⇒ y = (2/5)(30) = 12. Or, we could solve the first equation for 2x and substitute into the second: 2x=30-2y, y-2(2x) = 0 ⇒ y-2(30-2y) = 0 ⇒ y = 60/5 = 12.
The substitution property of equality says you can make any substitution of equal values anywhere. "butter = margarine" means you can substitute butter for margarine, or vice versa, wherever you may wish.
Evaluate the expression: y – y ÷ 1 + x Use x = 7 and y = 3
Hi ;-)
[tex]x=7 \ and \ y=3\\\\y-y:1+x=3-3:1+7=3-3+7=0+7=\boxed7[/tex]
can someone help me, please?
Answer:
0
2
-1
Step-by-step explanation:
from f(0) we find that
y = mx - 1
from f(-1) we find that the equation is
y = -3x - 1
1)
inverse f(x) :
x = -3y - 1
y = -(x + 1) / 3 x = -1
y = -(-1 + 1) / 3
y = 0
2)
y also equal to 0 since x = -1
3)
f^-1(2) = -(2+1) / 3
= -3/3
= -1
f(-1) = 2
Find the missing side length image below
Answer:
40
Step-by-step explanation:
Based on the Proportional Transversal Theorem, the three parallel lines hat intersects the two transversals, divides the transversal lines proportionally.
Therefore, we would have the following ratio:
28/35 = ?/50
Cross multiply
35*? = 50*28
35*? = 1,400
Divide both sides by 35
? = 1400/35
? = 40
A 230 pound man, a 140 pound woman, a 750 pound crate of equipment, an 80 pound bag of concrete. What percent of the total weight was concrete?
What percent of the total weight was human?
Solve the equation. If there is no solution, select no solution.
Answer:
no solution to the question
Answer:
4 2/3
Step-by-step explanation:
The two-step equation is solved regularly. The answer is 4 2/3.
A dodgeball team at Lincoln Elementary School needs a team of 4 in order to compete against other schools. If there are 9 kids that want to be part of the team, how many different ways can you pick a team of 4
Answer:
3 ways
Step-by-step explanation:
Find the missing side length in the image below
Answer:
? = 5
Step-by-step explanation:
Recall: when 2 transversal lines cuts across 3 parallel lines, the parallel lines are divided proportionally by the transversals.
Therefore:
?/10 = 3/6
Cross multiply
?*6 = 3*10
?*6 = 30
Divide both sides by 6
? = 30/6
? = 5
x = either 100 , 140 , or 120
Determine the sum of the measures of the exterior angles of a convex hexagon (6-sided polygon).
A. 540
B. 720
C. 1,080
D. 360
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Answer:
(d) 360°
Step-by-step explanation:
The sum of exterior angles of any convex polygon is 360°.
An automobile manufacturer has given its jeep a 51.3 miles/gallon (MPG) rating. An independent testing firm has been contracted to test the actual MPG for this jeep since it is believed that the jeep has an incorrect manufacturer's MPG rating. After testing 230 jeeps, they found a mean MPG of 51.1. Assume the population variance is known to be 6.25. A level of significance of 0.02 will be used. Make the decision to reject or fail to reject the null hypothesis.
Answer:
The p-value of the test is 0.2262 > 0.02, which means that the decision is to fail to reject the null hypothesis.
Step-by-step explanation:
An automobile manufacturer has given its jeep a 51.3 miles/gallon (MPG) rating.
At the null hypothesis, we test if the mean is of 51.3, that is:
[tex]H_0: \mu = 51.3[/tex]
An independent testing firm has been contracted to test the actual MPG for this jeep since it is believed that the jeep has an incorrect manufacturer's MPG rating.
This means that at the alternative hypothesis, we test if the mean is different of 51.3, that is:
[tex]H_0: \mu \neq 51.3[/tex]
The test statistic is:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.
51.3 is tested at the null hypothesis:
This means that [tex]\mu = 51.3[/tex]
After testing 230 jeeps, they found a mean MPG of 51.1. Assume the population variance is known to be 6.25.
This means that [tex]n = 230, X = 51.1, \sigma = \sqrt{6.25} = 2.5[/tex]
Value of the test statistic:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
[tex]z = \frac{51.1 - 51.3}{\frac{2.5}{\sqrt{230}}}[/tex]
[tex]z = -1.21[/tex]
P-value of the test and decision:
The p-value of the test is the probability of the sample mean differing from 51.1 by at least 0.2, which is P(|z| > 1.21), which is 2 multiplied by the p-value of z = -1.21.
Looking at the z-table, z = -1.21 has a p-value of 0.1131.
2*0.1131 = 0.2262
The p-value of the test is 0.2262 > 0.02, which means that the decision is to fail to reject the null hypothesis.
Find the volume of the figure. If necessary, round the answer to the nearest whole number.
Answer:
V = 108 ft³
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightGeometry
Volume of a Rectangular Prism Formula: V = lwh
l is lengthw is widthh is heightStep-by-step explanation:
Step 1: Define
Identify variables
l = 4 ft
w = 3 ft
h = 9 ft
Step 2: Find Volume
Substitute in variables [Volume of a Rectangular Prism Formula]: V = (4 ft)(3 ft)(9 ft)Evaluate [Order of Operations]: V = 108 ft³Find the difference: -18 - (-18)
Answer:
0
Step-by-step explanation:
-18-(-18)
= -18+18 [(+) + (+)=(+)]
=0 [(-) + (-)=(-)]
How to divided 245 by 70
Show your work
Answer:
Step-by-step explanation:
Hello!
2 4 5 ∟ 70
-2 1 3, 5
------------------------
3 5 0
3 5 0
- --------------------------------
0 0 0
evaluate the function f(x)=4x^2-7x+7 find f(7)
please I need the answer soon!
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Answer:
f(7) = 154
Step-by-step explanation:
The basic idea is you put 7 where x is and do the arithmetic.
Polynomial evaluation is sometimes easier if you rewrite it to Horner form.
f(x) = (4x -7)x +7
f(7) = (4·7 -7)(7) +7 = 21(7) +7 = 147 +7
f(7) = 154
Because of the relatively high interest rates, most consumers attempt to pay off their credit card bills promptly. However, this is not always possible. An analysis of the amount of interest paid monthly by a bank's Visa cardholders reveals that the amount is normally distributed with a mean of 27 dollars and a standard deviation of 9 dollars.
A. What proportion of the bank's Visa cardholders pay more than 29 dollars in interest?
B. What proportion of the bank's Visa cardholders pay more than 35 dollars in interest?
C. What proportion of the bank's Visa cardholders pay less than 14 dollars in interest?
D. What interest payment is exceeded by only 18% of the bank's Visa cardholders?
Answer:
a. 0.4129 = 41.29% of the bank's Visa cardholders pay more than 29 dollars in interest.
b. 0.1867 = 18.67% of the bank's Visa cardholders pay more than 35 dollars in interest.
c. 0.0742 = 7.42% of the bank's Visa cardholders pay less than 14 dollars in interest.
d. An interest payment of $35.2 is exceeded by only 18% of the bank's Visa cardholders.
Step-by-step explanation:
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Mean of 27 dollars and a standard deviation of 9 dollars.
This means that [tex]\mu = 27, \sigma = 9[/tex]
A. What proportion of the bank's Visa cardholders pay more than 29 dollars in interest?
This is 1 subtracted by the p-value of Z when X = 29, so:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{29 - 27}{9}[/tex]
[tex]Z = 0.22[/tex]
[tex]Z = 0.22[/tex] has a p-value of 0.5871.
1 - 0.5871 = 0.4129
0.4129 = 41.29% of the bank's Visa cardholders pay more than 29 dollars in interest.
B. What proportion of the bank's Visa cardholders pay more than 35 dollars in interest?
This is 1 subtracted by the p-value of Z when X = 35, so:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{35 - 27}{9}[/tex]
[tex]Z = 0.89[/tex]
[tex]Z = 0.89[/tex] has a p-value of 0.8133.
1 - 0.8133 = 0.1867
0.1867 = 18.67% of the bank's Visa cardholders pay more than 35 dollars in interest.
C. What proportion of the bank's Visa cardholders pay less than 14 dollars in interest?
This is the p-value of Z when X = 14. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{14 - 27}{9}[/tex]
[tex]Z = -1.445[/tex]
[tex]Z = -1.445[/tex] has a p-value of 0.0742.
0.0742 = 7.42% of the bank's Visa cardholders pay less than 14 dollars in interest.
D. What interest payment is exceeded by only 18% of the bank's Visa cardholders?
This is the 100 - 18 = 82nd percentile, which is X when Z has a p-value of 0.82, so X when Z = 0.915.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]0.915 = \frac{X - 27}{9}[/tex]
[tex]X - 27 = 0.915*9[/tex]
[tex]X = 35.2[/tex]
An interest payment of $35.2 is exceeded by only 18% of the bank's Visa cardholders.
At basketball practice, you made 59 out of 80 shots.
Which choice is closest to the percentage of shots you mad
Answer:
73.5 Percent ...........
Answer:
The closest percentage of shots you made is 75%. Please mark brainliest.
I believe the choices are:
60%
70%
75%
80%
Therefore the answer 75%
Step-by-step explanation:
59/80 = 0.7375
Rounded up is 0.75
0.75 x 100 = 75%
Hope this helps.
Have a nice day amazing person there.
MAY GOD RICHLY BLESS YOU!!
Regina has 3 bags of marbles. There are 25 marbles in each bag. She wants to put an equal number of marbles into 5 bags. Which expression would show how many marbles can go in each bag?
Answer:
(3 × 25)/5 marbles can go in each bag
Explanation:
Number of bags Regina has = 3
Number of marbles in each bag = 25
So, total number of marbles = 3 × 25
Number of marbles in each bag, if divided equally into 5 bags = (3 × 25)/5
Further:
Solving the expression,
(3 × 25)/5
= 75/5
= 15
So, the each bag has 15 marbles if they are equally divided into 5 bags.
Answer:
(25 x 3) / 5
Step-by-step explanation:
you have to do 25 x 3 to get the total amount of marbles. Then you have to divide that by the amount of bags.
Probability that a person is chosen at random
Answer:
152 / 370
Step-by-step explanation:
Total number of people
152+218 = 370
P( own a dog) = people said yes / total
= 152 / 370
These two cones are similar. What is the value of x?
Answer:
A
Step-by-step explanation:
Given that the cones are similar then corresponding dimensions are in proportion, that is
[tex]\frac{12}{2}[/tex] = [tex]\frac{3}{x}[/tex] ( cross- multiply )
12x = 6 ( divide both sides by 12 )
x = 0.5 → A
8x=3x²-1 plz help me show your work
Answer:
Step-by-step explanation:
3 times 8= 24 • 24 = 576 - 1 =575
or
3•8=24•2=48-1=47
not sure
Answer:
The answer is [tex]x=\frac{4(+-)\sqrt{19} }{3}[/tex] in exact form or [tex]x=2.7863[/tex], [tex]x=-0.1196[/tex] in decimal form.
Step-by-step explanation:
To solve this equation, start by moving all expression to the left side of the equation, which will include subtracting [tex]3x^2[/tex] and adding 1 to both sides of the equation. The equation will look like [tex]8x-3x^2+1=0[/tex].
Then, use the quadratic formula to find the solutions to the equation. The quadratic formula looks like [tex]\frac{-b(+-)\sqrt{b^2-4ac} }{2a}[/tex].
For this problem, the quadratic variables are as follows:
[tex]a=-3\\b=8\\c=1[/tex]
The next step is to substitute the values [tex]a=-3[/tex], [tex]b=8[/tex], and [tex]c=1[/tex] into the quadratic formula and solve for x. The quadratic formula will look like [tex]\frac{-8(+-)\sqrt{8^2-4(-3)(1)} }{2*-3}[/tex]. To simplify the equation, start by simplifying the numerator, which will look like [tex]x=\frac{-8(+-)2\sqrt{19} }{2*-3}[/tex]. Then, multiply 2 by -3 and simplify the equation, which will look like [tex]x=\frac{4(+-)\sqrt{19} }{3}[/tex]. The final answer is [tex]x=\frac{4(+-)\sqrt{19} }{3}[/tex] in exact form. In decimal form, the final answer is [tex]x=2.7863[/tex], [tex]x=-0.1196[/tex].
In the arithmetic sequence -7, -6, -5 what term is 2?
The term 2 is the ___th term of the sequence
Answer:
10th term
Step-by-step explanation:
The equation of the arithmetic sequence is an=-7+(n-1)*1=-8+n, plugging in 2 and solving for n we have
2=-8+n, n=10
how many feet is in one centimeter and how many inches is in 1 feet?
Answer:
12 inches r in a foot
0 feet r in a centimeter
Step-by-step explanation:
Answer:
0.032 feet in a centimeter and 12 inches in 1 foot
Step-by-step explanation:
hope it helps pls mark as brainliest!
Please help I will mark brainliest to who ever is rigjt
Answer:
(1,0) and (0,4)
Step-by-step explanation:
Crosses the x axisWhen f(x) will cross the x axis, the y coordinate will turn 0, so 0=-5^(x)+5, 5=5^(x) Which is possible when x=1. So (1,0)
Crosses the y axisWhen f(x) will cross the y axis, the x coordinate will turn 0, so f(0)=-5^(0)+5, f(0)=-1+5=4. So (0,4)
what is the area of triangle JHK?
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Answer:
4.18 square units
Step-by-step explanation:
The area is given by the formula ...
A = 1/2bh
where b is the length of the base, and h is the perpendicular distance from the base to the opposite vertex.
A = 1/2(2.2)(3.8) = 4.18 . . . square units
what is the sum of √-2and√-18
For this question, we need to simplify some radicals and combine like terms. One thing for sure that should be noticed is the fact that both of these radicals are going to be imaginary, as they both have negatives inside of them.
Let's simplify the radicals:
√-2 = ← Note the negative
i√2
√-18 = ← Note the negative here as well
i√18 =
i√2·3·3 =
i√2·3² =
3i√2
Now, all we have to do is combine like terms:
i√2 + 3i√2 = 4i√2
e/22 = 6/15, What does e equal? Please answer with work!
Answer:
e = 44/5 = 8.800
Step-by-step explanation:
Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :
e/22-(6/15)=0
Step by step solution :
STEP
1
:
2
Simplify —
5
Equation at the end of step
1
:
e 2
—— - — = 0
22 5
STEP
2
:
e
Simplify ——
22
Equation at the end of step
2
:
e 2
—— - — = 0
22 5
STEP
3
:
Calculating the Least Common Multiple :
3.1 Find the Least Common Multiple
The left denominator is : 22
The right denominator is : 5
Number of times each prime factor
appears in the factorization of:
Prime
Factor Left
Denominator Right
Denominator L.C.M = Max
{Left,Right}
2 1 0 1
11 1 0 1
5 0 1 1
Product of all
Prime Factors 22 5 110
Least Common Multiple:
110
Calculating Multipliers :
3.2 Calculate multipliers for the two fractions
Denote the Least Common Multiple by L.C.M
Denote the Left Multiplier by Left_M
Denote the Right Multiplier by Right_M
Denote the Left Deniminator by L_Deno
Denote the Right Multiplier by R_Deno
Left_M = L.C.M / L_Deno = 5
Right_M = L.C.M / R_Deno = 22
Making Equivalent Fractions :
3.3 Rewrite the two fractions into equivalent fractions
Two fractions are called equivalent if they have the same numeric value.
For example : 1/2 and 2/4 are equivalent, y/(y+1)2 and (y2+y)/(y+1)3 are equivalent as well.
To calculate equivalent fraction , multiply the Numerator of each fraction, by its respective Multiplier.
L. Mult. • L. Num. e • 5
—————————————————— = —————
L.C.M 110
R. Mult. • R. Num. 2 • 22
—————————————————— = ——————
L.C.M 110
Adding fractions that have a common denominator :
3.4 Adding up the two equivalent fractions
Add the two equivalent fractions which now have a common denominator
Combine the numerators together, put the sum or difference over the common denominator then reduce to lowest terms if possible:
e • 5 - (2 • 22) 5e - 44
———————————————— = ———————
110 110
Equation at the end of step
3
:
5e - 44
——————— = 0
110
STEP
4
:
When a fraction equals zero :
4.1 When a fraction equals zero ...
Where a fraction equals zero, its numerator, the part which is above the fraction line, must equal zero.
Now,to get rid of the denominator, Tiger multiplys both sides of the equation by the denominator.
Here's how:
5e-44
————— • 110 = 0 • 110
110
Now, on the left hand side, the 110 cancels out the denominator, while, on the right hand side, zero times anything is still zero.
The equation now takes the shape :
5e-44 = 0
Solving a Single Variable Equation:
4.2 Solve : 5e-44 = 0
Add 44 to both sides of the equation :
5e = 44
Divide both sides of the equation by 5:
e = 44/5 = 8.800
One solution was found :
e = 44/5 = 8.800
Answer:
e =44/5
Step-by-step explanation:
e 6
----- = --------
22 15
Using cross products
e * 15 = 6 *22
15e = 132
Divide by 15
15e/15 = 132/15
e =44/5
Find the value of this expression
Answer:
[tex] \frac{(3) ^{2} + 3}{3 - 1} [/tex]
[tex] \frac{9 + 3}{3 - 1} [/tex]
[tex] \frac{12}{2} [/tex]
= 6
The percent of data between z=0.23 and z = 1.27 is
(Round to two decimal places as needed.)
Answer:
0.40905 - 0.10204 = .30701 = 30.7 %
Step-by-step explanation:
0.23 0.40905
1.27 0.10204
If the terminal side of an angle (θ) goes through the point (4 , -3) what is (θ)?
Answer:
The family of directions of the given vector is represented by [tex]\theta = 323.130^{\circ} \pm 360\cdot i[/tex], [tex]\forall \,i\in \mathbb{N}_{O}[/tex].
Step-by-step explanation:
According to the given information, vector stands in the 4th Quadrant ([tex]x > 0[/tex], [tex]y < 0[/tex]) and direction of the vector ([tex]\theta[/tex]) in sexagesimal degrees, is determined by following definition:
[tex]\theta = 360^{\circ} - \tan^{-1} \left(\frac{|y|}{|x|} \right)\pm 360\cdot i[/tex], [tex]\forall \,i\in \mathbb{N}_{O}[/tex]
Please notice that angle represents a function with a periodicity of 360°.
If we know that [tex]x = 4[/tex] and [tex]y = -3[/tex], then the direction of the vector is:
[tex]\theta = 360^{\circ}-\tan^{-1}\left(\frac{|-3|}{|4|} \right)\pm 360\cdot i[/tex]
[tex]\theta = 323.130^{\circ} \pm 360\cdot i[/tex]
The family of directions of the given vector is represented by [tex]\theta = 323.130^{\circ} \pm 360\cdot i[/tex], [tex]\forall \,i\in \mathbb{N}_{O}[/tex].
Which of the following behaviors would best describe someone who is listening and paying attention? a) Leaning toward the speaker O b) Interrupting the speaker to share their opinion c) Avoiding eye contact d) Asking questions to make sure they understand what's being said
Answer:
D
Step-by-step explanation:
If you ask questions while their speaking it shows that you are paying attention to them. Avoiding eye contact could mean your thinking about something else or you aren't interested. Interrupting them is just being disrespectful. Leaning towards them doesn't really do anything other than you moving.