ANSWER
a=-2, b=3
EXPLANATION
The given equation is

Recall that:

We simplify the left hand side to get:

For this equation to be true, we must have:
-6a=12 and 2+b=5
This implies that,
a=-2 and b=3
You subtract 5 to the other side so it'll read -6n=-4 then divide -6 to the other side and it'll be 2/3
It would 144 sq ft
2*24= 48
48-4=44
50*2=100
100+44=144