Question 268163
Area of original square = x^2
Area of new square = (x+7)^2 = 121.
{{{(x+7)^2 = 121}}}
step 1 - tale a square root to get
{{{(x+7) = 11}}}
step 2 - subtract 7 to get
{{{x = 4}}}
length of a side of the original square is 4 cm