Question

If a + 2 b equal to -3 C then prove that a cube + 8 b cube + 27 C cube equal to 18 ABC

Answer 1

Given, a+2b=-3c

=>a+2b+3c = 0

Here,x+y+z=0

So, x³+y³+z³=3xyz

=>(a)³+(2b)³+(3c)³= 3*a*2b*3c

                            =18abc

Hence, Proved.

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