Without actually calculating the cubes, find he value of the following: (28)3 + (−15)3 + (−13)3
(28)3 + (−15)3 + (−13)3
∵ (28) + (-15) + (-13) = 0
Using identity, if x + y + z = 0, then x3 + y3 + z3 = 3xyz.
= 3 × (28) × (-15) × (-13) = 16380 ...(answer)