SOLUTION: If the sides of a square are decreased by 3 cm, the area is decreased by 81 cm^2. What were the dimensions of the origional square?

Algebra ->  Human-and-algebraic-language -> SOLUTION: If the sides of a square are decreased by 3 cm, the area is decreased by 81 cm^2. What were the dimensions of the origional square?      Log On


   

Question 55157This question is from textbook Beginning Algebra
: If the sides of a square are decreased by 3 cm, the area is decreased by 81 cm^2. What were the dimensions of the origional square? This question is from textbook Beginning Algebra

Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
(X-3)(X-3)=X^2-81
X^2-6X+9=X^2-81
-6X=-81-9
6X=90
X=90/6
X=15
PROOF
(15-3)(15-3)=15*15-81
12*12=225-81
144=144