Question

Carry out the multiplication of the expressions in each of the following pairs.

(i) 4p, q + r (ii) ab, a − b (iii) a + b, 7a²b²

(iv) a² − 9, 4a (v) pq + qr + rp, 0

Answer 1

(i) (4p) × (q + r) = (4p × q) + (4p × r) = 4pq + 4pr

(ii) (ab) × (a − b) = (ab × a) + [ab × (− b)] = a²b − ab²

(iii) (a + b) × (7a² b²) = (a × 7a²b²) + (b × 7a²b²) = 7a³b² + 7a²b³

(iv) (a² − 9) × (4a) = (a² × 4a) + (− 9) × (4a) = 4a³ − 36a

(v) (pq + qr + rp) × 0 = (pq × 0) + (qr × 0) + (rp × 0) = 0