Question

Evaluate (105)3 using a suitable identity

Answer 1

105=(100+5)^3 Identity applied vl be (a+b)^3= a^3+b^3+3a^2b+3ab^2 Put a=100 and b=5 = 100^3+5^3+3×100^2×5+3×100×5^2 = 1000000+150000+7500 =1157500

Answer 2

Answer:

1157625

Step-by-step explanation:

(105)^3 = (100+5)^3                                    (a+b)^3=a^3 + b^3 + 3 ab^2 + 3 a^2b

    100^3+5^3+3 x 100^2 x 5+3 x 100 x 5^2

= 1000000+125+150000+7500

= 1150000+7625

= 157625