Question 345043
If one side of a square is increased by 8 feet
 and an adjacent side decreased by 2 feet, 
a rectangle is formed whose perimeter is 40 feet.
 Find the length of a side of the square.
:
Let x = side of the square
then
(x+8) = the length of the rectangle
and
(x-2) = the width
:
The perimeter:
2(x+8) + 2(x-2) = 40
Simplify, divide by 2
x + 8 + x - 2 = 20
2x + 6 = 20
2x = 20 - 6
x = {{{14/2}}}
x = 7 ft is the side of the square
:
:
Check solution by finding the perimeter of the rectangle when x = 7
2(7+8) + 2(7-2) =
2(15) + 2(5) = 40