SOLUTION: The outside of a picture frame measures 12cm by 20cm: 84cm squared of picture shows. ?Find the width of the frame? I have to show my work?

Algebra ->  Rectangles -> SOLUTION: The outside of a picture frame measures 12cm by 20cm: 84cm squared of picture shows. ?Find the width of the frame? I have to show my work?      Log On


   

Question 311553: The outside of a picture frame measures 12cm by 20cm: 84cm squared of picture shows. ?Find the width of the frame?
I have to show my work?
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
(12-X)(20-X)=84
240-20X-12X+X^2=84
X^2-32X+240-84=0
X^2-32X+156=0
(X-6)(X-26)=0
X-6=0
X=6 CM. ANS. FOR THE WIDTH OF THE FRAANE.
PROOF:
(12-6)(20-6)=84
6*14=84
84=84