Question

Without actually calculating the cubes, the value of (28)^3 + (-15)^3 + (-13)^3

Answer 1

(28)(-15)(-13)=3xyz

=3×28×-15×-13

=. -4539

Answer 2

Answer:

Let a=(28), b=(-15), c=(-13)

a+b+c=28+(-15) +(-13) =28-28=0.

Therefore,

(a) ^3+(b) ^3+(c) ^3-3abc=0

(a) ^3+(b) ^3+(c) ^3=3abc

(28) ^3+(-15) ^3+(-13) ^3=3(28) (-15) (-13) =16380