If the sides of a square are lenthened by 7 cm, the area becomes 222 cm squared. Find the length of a side of the original square.

3 answers

225 cm squared....sorry
A = s^2

Square root of 225 = 15

15-7 = ?
first, represent:
let x = the length of the original square
let x+7 = the length of the new square

since area of square is (length of side)^2:
A=s^2
225=(x+7)^2
225=x^2+14x+49 *transpose all terms to one side
x^2+14x-176=0
(x-8)(x+22)=0 *get only the positive since there is no negative length
therefore,
x=8 cm

so there,, =)