A rectangle is three times as long as it is wide. If its length and width are both decreased by 2cm, its area is decreased by 36cm^2. Find its original dimensions.
A rectangle is three times as long as it is wide. If its length and width are both decreased by 2cm, its area is decreased by 36cm^2. Find its original dimensions.
Denote the original length to be $\displaystyle L$ and its original width to be $\displaystyle W$.
From the first sentence, you know $\displaystyle 3W=L$
The second one tells you that $\displaystyle (L-2)(W-2)=LW-36$