Opposite value would be either changing from a positive to a negative or from a negative to a positive.
Absolute value is always a positive value
A) 7.2, -7.2, 7.2
B) -3.5, 3.5, 3.5
C) 5 1/2, -5 1/2, 5 1/2
Just multiply all of them because Volume = Length x Width x Height. So it's 8.5 x 4.5 x 3.75. That equals 143.4375. Cubic inches is just there after you multiply, so you don't have to convert anything. So it's 143.4375 cubic inches.