The sum of two numbers will be zero when you have the same number and one is positive and one is negative. For example 1 + -1= 0
Started out with 32/32. They ate 18/32, 32-18=14; 14/32. To simplify, 7/16 was left.
8 - {x - (5 + x)}
= 8 - {x - 5 - x}
= 8 + 5
= 13
