C = 3b+2d is the same as 3b+2d = C
Let's isolate d. To do this, we first need to subtract 3b from both sides
3b+2d = C
3b+2d-3b = C-3b
2d = C-3b
Then divide both sides by 2
2d = C-3b
2d/2 = (C-3b)/2
d = (C-3b)/2
Take note of the parenthesis as they are very important. We want to divide ALL of C-3b over 2. We don't want to just divide -3b over 2.
The answer choices you have aren't 100% clear but I have a feeling your teacher meant to say d = (C-3b)/2 instead of d = C-3b/2 for choice A
If that assumption is correct, then the answer is choice A.
If you have a problem like:
4x+2y=20
2x+2y=16
You would subtract
4x-2y=20
-2x+2y=16
You would get the new problum
2x=4
You now want to divide the 2 on both sides to solve for x
x=2
Now that you've solved for X you want to solve for y. So use substitution to solve for y. You would want to substatute the x for the 2 in either of the problums. I'll use the first one.
4(2)+2y=20
You first want to multiply te 4(2) you would get a new problum.
8+2y=20
Now you want to subtract the 8 on both sides.
2y=12
The last step to solve for y is to divide the 2 on both sides.
Y=6
So your answers would be
x=2
y=6
If you’re looking for x it would be -4/3
Answer:
The standard deviation will remain unchanged.
Step-by-step explanation:
Given
Solving (a): The range
This is calculated as:
Where:
So:
Solving (b): The variance
First, we calculate the mean
The variance is calculated as:
So, we have:
![\sigma^2 =\frac{1}{6-1}*[(136 - 135)^2 +(129 - 135)^2 +(141 - 135)^2 +(139 - 135)^2 +(138 - 135)^2 +(127 - 135)^2]](https://tex.z-dn.net/?f=%5Csigma%5E2%20%3D%5Cfrac%7B1%7D%7B6-1%7D%2A%5B%28136%20-%20135%29%5E2%20%2B%28129%20-%20135%29%5E2%20%2B%28141%20-%20135%29%5E2%20%2B%28139%20-%20135%29%5E2%20%2B%28138%20-%20135%29%5E2%20%2B%28127%20-%20135%29%5E2%5D)
![\sigma^2 =\frac{1}{5}*[162]](https://tex.z-dn.net/?f=%5Csigma%5E2%20%3D%5Cfrac%7B1%7D%7B5%7D%2A%5B162%5D)
Solving (c): The standard deviation
This is calculated as:
--- approximately
Solving (d): With the stated condition, the standard deviation will remain unchanged.
