Question

Find the product, using suitable properties:
(a) 26 $\times$ (− 48) + (− 48) $\times$ (− 36)
(b) 15 $\times$ (− 25) $\times$ (− 4) × (− 10)
[4 MARKS]

Answer 1

Each option: 2 Marks

(a) 26 $\times$ (−48) + (−48) $\times$ (−36)
= (−48) $\times$ 26 + (−48) $\times$ (−36)
($\because$ (b $\times$ a = a $\times$ b))
= (−48) [26 − 36] (a $\times$ b + a $\times$ c) = a (b + c)
= (−48) $\times$ (−10) = 480

(b) 15 $\times$ (−25) $\times$ (−4) $\times$ (−10)
= 15 $\times$ [(−25) $\times$ (−4)] $\times$ (−10)
= 15 $\times$ [100] $\times$ (−10)
= 15 $\times$ (−1000) = −15000