Question

Answer it and I will mark it as brainliest

Answer 1

Let (-12)=a , 7=b, 5=c

So here a+b+c =-12+7+7=0

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

But here a+b+c=0

So, a^3+b^3+c^3-3abc=0
a^3+b^3+c^3=3abc

So,

(-12)^3+(7)^3+(5)^3=3(-12)(7)(5)
=3(-12×7×7)
=3(-420)
=(-1260)

ANSWER :- Here, (-12)^3+(7)^3+(5)^3=(-1260)

If you find it helpful please mark it as brainliest....

Answer 2

Hey Hanu,

Here is your solution :

We have to find the value of ( -12 )³ + 7³ + 5³ without actually finding its cube.

= ( -12 )³ + 7³ + 5³

Let , ( -12 ) = a , 7 = b and 5 = c.

= ( a )³ + ( b )³ + ( c )³

By adding a , b and c.

⇒ a + b + c = -12 + 7 + 5 = -12 + 12 = 0

Using identity for :

 [ ( a + b + c = 0 ) , then ( a³ + b³ + c³ = 3abc ) ]

= 3 abc

By putting back the values of a , b and c.

= 3 ( -12 ) ( 7 ) 5

= -1260

The required answer is -1,260.

Hope it helps !!