Answer: p = -2/3, sum = 0
Explanation:
Additive inverse has the name numerical value as the given number but has the opposite sign so when they are added together they equal zero. The sum of any number and its additive inverse equal 0.
EX: 1 and -1
1+ (-1) = 0
EX: -4.5 and 4.5
-4.5 + 4.5 = 0