Question

y^2 + 8y-20

Answer 1

Factorise?

Answer 2

y^2 - 2y + 10y - 20
= y(y - 2) + 10(y - 2)
= (y - 2)(y + 10)

Answer 3

y = {-8 ± [√(8^2 - 4(-20)]}/2 = -4 ± 12 = 8 or -16