Answer:
c. 4
Explanation:
The area of a rectangle is base times height. The base here is x, and the height is x*5. So you have the equation:
x(x+5)=36
x^2+5x=36
x^2+5x-36=0
(x+9)(x-4)=0
x=-9,4
However, distance cannot be negative, so x must equal 4.
Although, keep in mind, you could have just done guess and check and it wouldnt have taken that long.