Question

Evaluate cube of 30+cube of (-18) +cube of (-12) using suitable identity​

Answer 1

Answer:

30³ = 27,000

(-18)³ = -5,832

(-12)³ = -1,728

Step-by-step explanation:

27,000+(-5,832)+(-1,728)

=27,000-5,832-1,728

=21,168-1,728

=19,440

Answer 2

Answer:

$a = 30 \\ b = - 18 \\ c = - 12 \\ a + b + c = 30 + ( - 18) + ( - 12) \\ 30 - 18 - 12 = 0 \\ \\ a + b + c = 0 \\ {a}^{3} + {b}^{3} + {c}^{3} = 3abc \\ ( {30}^{3} )+ ( { - 18}^{3} ) + ( { - 12}^{3}) = 3 \times 30 \times ( - 18) \times ( - 12) \\ = 90 \times 216 \\ = 19440$