what is the identity for (x-a)(x-b)
= (x - a)(x - b)
= x(x - b) - a(x - b)
= x2 - xb - ax + ab
= x2 - x(a + b) + ab
So, (x - a)(x - b) = x2 - x(a + b) + ab
= x(x - b) - a(x - b)
= x2 - xb - ax + ab
= x2 - x(a + b) + ab
So, (x - a)(x - b) = x2 - x(a + b) + ab