Question

Find the product, using suitable properties:
(a) 625 $\times$ (− 35) + (− 625) $\times$ 65
(b) (− 17) $\times$ (− 29)
[4 MARKS]

Answer 1

Each option: 2 Marks
a) 625 $\times$ (−35) + (−625) $\times$ 65
= 625 $\times$ [(−35) + (−65)]
($\because$ (a $\times$ b) + (a $\times$ c) = a $\times$ (b + c))
= 625 $\times$ (−100) = −62500

b) (−17) $\times$ (−29)
= (−17) $\times$ [−30 + 1]
= [(−17) $\times$ (−30)] + [(−17) $\times$ 1]
($\because$ a $\times$ (b + c) = (a $\times$ b) + (a $\times$ c)
= (510) + (−17) = 493