Question

Find the value using suitable property.
i) 8 × 53 × (-125)
ii) (-47) × 102
iii) 4574 x 99 - ( -4574)
iv) 2369x (-487) – 1369 x (-487)
v) 25 × 15 × 4 × 6

Answer 1

i) 8 × 53 × (-125)
We use the property: A positive number multiplied by a negative number gives a negative number

= 53 x(8x(-125)) : Associative property of multiplication
=53x-1000
=-53000

ii) (-47) × 102

= (3-50)x(100+2)
=3x100 + 3x2 - 50x100 - 50x2 (Distributive property)
=300 + 6 - 5000 - 100
=206-5000
= -4794

iii) 4574 x 99 - ( -4574)
We use the property: A negative number multiplied by a negative number gives a positive number
= 4574 x 99 + 4574
=4574(99+1) Factor out the 4574 (The opposite of distributive property)
=4574 (100) Bodmas
=457400

iv) 2369x (-487) – 1369 x (-487)
= (-487) (2369 - 1369) Factor out the (-487) (The opposite of distributive property)
=(-487) (1000) Bodmas
=-487000

v) 25 × 15 × 4 × 6
= 25x4 x 15x6 Associative property of multiplication
= 100 x 90
=9000