Answer:
65
Step-by-step explanation:
35+40+27+42+45+50=249 249+65=315 315/7=45
There isn't enough information; however, let's say you were to find the missing side length of a rectangle. The perimeter is 52 and the two given side lengths are both 16. You would set up an equation to find the missing side lengths:
52 = 16 + 16 + ? + ?
52 = 32 + ? + ?
20 = ? + ?
Since this is a rectangle, the two other sides have to be equal. Therefore, you would divide the number by 2.
10 = ?
Answer: 
Step-by-step explanation:
You have the equation
.
Then, to solve for the variable
from the equation you need:
Make the subtraction of the right side of the equation:
(As the denominators are 1 and
, the least common denominator is
)

Multiply
to both sides:

Add
to both sides:

And finally divide both sides by
:

You'd times15x25 and you'll gladly get the answer
I think what you need to do is make B = -5
3a = -2(-5) - 7
3a = 10 - 7
3a = 3
a = 1