Question 313948
W=L+10
A=LW
A=L(L+10)
1,200=L^2+10L
L^2+10L-1,200=0
(L-30)(L+40)=0
L-30=0
L=30 ANS. FOR THE WIDTH.
W=30+10=40 ANS. FOR THE LENGTH.
PROOF:
1,200=30*40
1,200=1,200