Question

without calculating cubes find value of (-13)cube +(-7) cube+(20)cube

Answer 1

Answer:

use formula 3abc

3*-13*-7*20=5460 ans..

Answer 2

Answer:

if a+b+c=0,a cube + b cube + c cube=3abc

then (-13 +(-7)+20)=0,

(-13)cube +(-7) cube + (20)cube =3(-13)(-7)(20)

=5803

hope it helps u