Answer is 16
8 (6 1/4 x 3.2 - 18)
8 ( 6x4+1) = 25/4
8 (25/4 x 3.2 - 18)
8 (25/4 x 3.2) = 80/4 = 20
8 (20 - 18) = 2
8 x 2 = 16
Surface area of a cube is given by
SA=6a²
but
SA=150 in²
thus
150=6a²
solving for a we obtain:
150/6=a²
a²=25
thus
a=√25
a=5 inches
hence the side length is 5inches
The commutative property of multiplication.