Question

Without actually calculating the cubes, find the value of each of the following:

(i) (−12)3+(7)3+(5)3​

Answer 1

Answer:

Answer

Correct option is

A

1260

(−12)  

3

+(7)  

3

+(5)  

3

 

Consider, a=−12,b=7,c=5

Then,  

a+b+c=(−12)+7+5=0

Using, a  

3

+b  

3

+c  

3

=3abc, Ifa+b+c=0

So, (−12)+7  

3

+5  

3

 

      =3×(−12)×7×5

      =−1260

its hard to read but hope it hepled