Question 130570
W=L-12 OR 2(L-12)+2L=P OR 2L-24+2L=P OR 4L-24=P ORIGINAL PERIMETER.
2(L-12+30)+2(L+30)=2P OR 2L+36+2L+60=2P OR 4L+96=2P DOUBLED PERIMETER.
NOW MULTIPLY THE FIRST EQUATION BY 2 & SET THEM EQUAL.
2(4L-24)=4L+96
8L-48=4L+96
8L-4L=96+48
4L=144
L=144/4
L=36 IS THE ORIGINAL LENGTH.
W=36-12
W=24 FOR THE ORIGINAL WIDTH.
PROOF
2*24+2*36=48+72=120
2(24+30)+2(36+30)=2*54+2*66=108+132=240
240=2*120
240=240