Answer:
X = 2, -8
Step-by-step explanation:
for the triangle...
b=2h
a=(1\2).bh=648
(1/2).2h.h=648
h2=648
h-18|2 in
h=36|2 in
for the rectangle...
L=3+w
a=l+w=648
{3+w}w=648
w2+3w-648=0
Only positive W values make sense here..
w-24=0
w=24 in
So..
L=3+24
Second option, just do Pemdas backwards.