Question

Evaluate without actually calculating cubes (28)^3+(-15)^3+(-13)^3

Answer 1

If a+b+c = 0

Then, a^3+b^3+c^3 = 3abc

Use this to get your answer

Answer 2

we know ,

if a + b + c = 0

then , a³ + b³ + c³ = 3 × a × b × c = 3abc

therefore ,

a = 28 , b = -15 , c = -13

=> a + b + c = 28 - 15 - 13 = 0

so ,

28³ + (-15) ³ + (-13)³ = 3 × 28 × (-15) × (-13)

=> 28³ + (-15) ³ + (-13)³ = 16380