Each side of a square is increased 3 inches. When this happens, the area is multiplied by 9. How many inches in the side of the original square?

Question

Each side of a square is increased 3 inches. When this happens, the area is multiplied by 9. How many inches in the side of the original square?

Answer 1

A=s^2

A=(s+3)^2

A=s^2+6s+9

s^2+6s+9=9*s^2

9s^2-s^2-6s-9=0

8s^2-6s-9=0

factor

8*9=2*2*2*3*3=(2*2*3)*(2*3)=12*6 and 12-6=6

(4s+3)(2s-3)=0

2s-3=0

2s=3

s=3/2

s=1.5 inches

A=(1.5)^2=2.25

add 3

A=(4.5)^2=20.25

20.25 is 9 times 2.25