Question

14. Without actual calculating the cubes, find the value of each of the following
(i) (-10)3 + (7)3 + (3)3
​

Answer 1

Answer:

We know the corollary: if a+b+c=0 then a

3

+b

3

+c

3

=3abc

Using the above corollary taking a=−10, b=3 and c=7, we have a+b+c=−10+3+7=0 then the value of (−10)

3

+(3)

3

+(7)

3

is:

(−10)

3

+(3)

3

+(7)

3

=3(−10×3×7)=−630

Hence, (−10)

3

+(3)

3

+(7)

3

=−630