Question 92881
Let the original length of each side = x in. Then, original area = {{{x^2}}} sq in.


Then, the final length of each side = (x + 3) in and final area = {{{(x + 3)^2}}} sq in.


Hence, the increment in area 
= {{{(x+3)^2 - x^2}}} sq. in
= {{{6x+9}}} sq. in
This value is equal to 39 sq. in.


Hence, {{{6x + 9 = 39}}}
{{{6x = 39 - 9 = 30}}}
{{{x = 30/6 = 5}}}


Ans: Original length of the sides of the square were 5 inches.