Question

Use the formula to multiply:

(7) (10 + m) (1 + m)

Answer 1

As (x + a) (x + b) = x² + (a + b)x + ab
So, (10 + m) (1 + m) = (m + 10) (m + 1)
= m² + (1 + 10)m + 10
= m² + 11m + 10

∴ (10 + m) (1 + m) = m² + 11m + 10