Question

Verify the following

(i) 18 x 7 + (-3) = [18 x 7] + [18 x (-3)]
(ii) (-21) x [(-4) + (-6)] = [(-21) x (4)] + [(-21) x (-6)]

Answer 1

(i) 18 x [7 + (-3)] = 18 x 4 = 72

and [18 x 7] + [18 x (-3)] = 126 – 54 = 72

so 18 x [7 + (-3)] = [18 x 7] + [18 x (-3)]

(ii) (-21) x [(- 4) +(6)] = (-21) x (- 4 – 6) |

= (-21) x (-10) = 210

and [(21) x(-4)] + [(-21) x (-6)] = 84 + 126 = 210

so (-21) x [(- 4) + (-6)] = [(-21) x (- 4)] + [(-21) x (-6)]