Question

In this sum which identity is used???

Answer 1

a^3 + b^3 + c^3 - 3abc = (a+b+c) (a^2 + b^2 + c^2 - ab - bc -ca)

Answer 2

Given : (-17)^3 + (12)^3 + (5)^3.

Let a = -17, b = 12, c = 5.

Then,

= > a + b + c

= > -17 + 12 + 5

= > -5 + 5

= > 0.

We know that when a + b + c = 0, then a^3 + b^3 + c^3 = 3abc.

= > 3(-17)(12)(5)

= > -3060.

Therefore, (-17)^3 + (12)^3 + (5)^3 = -3060.

Hope it helps!