Question

Without actually calculating cubes, find value of (15) cube + (-9)cube +(-6) cube​

Answer 1

Step-by-step explanation:

(15)cube+(-9) cube + (-6) cube

use the formula = a cube + b cube + c cube

= a²+b²+c²+ 2( ab)+ 2(bc)+2(ac)

= (15)²+(-9²)+(-6²)+2(15*-9)+2*(-9*-6)+2(15*-6)

=225+81+36-270+108-180

= 0

Answer 2

Step-by-step explanation:

We know that if,

x + y + z = 0,

then x³ + y³ + z³ = 3xyz

→15³ + (-9)³ + (-6)³ = 3(15× -9× -6)

→15³ + (-9)³ + (-6)³ = 3(810)

→15³ + (-9)³ + (-6)³ = 2430