Question 198912
(20-2X)(30-2X)=264
600-60X-40X+4X^2=264
4X^2-100X+600-264=0
4X^2-100X+336=0
4(X^2-25X+84)=0
4(X-21)(X-4)=0
X-21=0
X=21 ANS.
X-4=0
X=4 ANS.