Question

Write an equation to express the value of h + k

Answer 1

The answer you want is 0, let's say h=-1 that means k=1 so -1+1=0

Answer 2

So since, they are the same distance from zero, they should be the oppposite of each other so in other words, k=-h and h=-k

so k+h=(subisute)k-k=-h+h=0 because they cancel