User Forum

Subject :IMO    Class : Class 9

The value of (xa)3 + (xb)3 + (xc)3 –3(xa)(xb)(xc), when a + b + c = 3x is ______.

A 3
B 2
C 1
D 0


I couldn't understand the solution given by you

Ans 1:

Class : Class 9
the answer is 0 . i hope you know the formula a^3 + b^3 + c^3 - 3abc =0 , when a+b+c = 0. take x-a = p, x-b=q and x-c=r. so a/q we have to find p^3 + q^3 + r^3 - 3pqr. now notice p+ q+ r= x-a+x-b+x-c = 3x-a-b-c = 0. so p^3 + q^3 + r^3 - 3pqr =0 as p+q+r=0

Post Your Answer