The answer is 0. the additive inverse of a negative number is the same number but positive. to find the sum means to add them together. for example take 2 and -2. 2 is the additive inverse of -2. if you add 2+-2 the answer comes out to 0
The answer would be 240 since you are only looking for surface area, which means you wouldn’t include the width
24 in²
6x4-24
multiply the base times the height.