Question

Without actually calculating the cubes,find the value of :20^3+10^3-30^3

Answer 1

as we know if a+b+c=0 then a^3+b^3+c^3=3abc

20+10-30=0

therefore,

20^3+10^3+(-30)^3= 3*20*10*(-30)
= -18000...