Question 16587
I'm not sure the above is correct: 

Area of a rectangle is length*width, and each side is going to increased by the same amount to get the new area of 63.

(7+x)(5+x)=63
35+12x+x^2=63
x^2+12x+35-63=0
x^2+12x-28=0
(x-2)(x+14)=0
x=2 and x=-14

Only logical solution is x=2

Check: (7+2)(5+2)=9*7. 9*7=63