Question

2. When do the two middle terms add to zero?

Answer 1

The middle terms add to zero when they have the same value and different signs, like

(x + 5)(x - 5) = (x)(x) + x(-5) + 5(x) + 5(-5)

When we find the middle terms they are

5(x) and x(-5)

5(x) = 5x

x(-5) = -5x

When we add them 5x + -5x the answer will be 0, because 5 + -5 = 0

So the middle term in the product of sum and difference is 0

(x + 5) and (x - 5) are sum and difference,

then the middle term in their product = 0

Answer 2

Answer: -5
Hope it helps