(3) Find the value of the following:
(a) 297 × 17 + 297 × 3
Sol.
= 297 × 17 + 297 × 3
= 297 x (17 + 3) ………………. taking 297 common
= 297 x 20
= 297 x 2 x 10
= (297 x 2) x 10
= 594 x 10
= 5940 Ans
b) 54279 × 92 + 8 × 54279
Sol.
= 54279 × 92 + 8 × 54279
= 54279 x (92 + 8) …………….. taking 54279 common
= 54279 x 100
=5427900 Ans.
(c) 81265 × 169 – 81265 × 69
Sol.
= 81265 × 169 – 81265 × 69
= 81265 x (169 – 69) ……………… taking 81265 common
= 81265 x 100
= 8126500 Ans.
(d) 3845 × 5 × 782 + 769 × 25 × 218
Sol.
= 3845 × 5 × 782 + 769 × 25 × 218
Here, there is nothing common to take
Let’s solve to find what to take common
= 3845 x 5 x 782 + 769 x (5 x 5) x 218
= 3845 x 5 x 782 + (769 x 5) x 5 x 218
= 3845 x 5 x 782 + 3845 x 5 x 218
= 3845 x 5 x (782 + 218) ……………………taking 3845 x 5 as common
= 3845 x 5 x 1000
= 19225 x 1000 = 19225000 Ans