Perimeter of a rectangel

Question

The length of a rectangle is x inches, its width is 3 inches shorter than the length. Compose an algebraic expression for the perimeter of the rectangle. Find the value of this expression if x =12.

Answer 1

Hello Yvette,

 

x = length of rectangle

x-3 = width of rectangle

 

P = 2W + 2L

 

Substituting what we have above

 

P = 2(x-3) + 2x

P = 2x-6+2x

P = 4x-6

 

If x = 12, then

P = 4(12) -6

P = 48-6=42