MathRevolution wrote:

If √x -√y+√z=0, which of the following is true?

A. x^2+y^2+z^2=xy+xz+yz

B. x^2+y^2+z^2=2xy+2xz+2yz

C. x^2+y^2-z^2=2xy+2xz-2yz

D. x^2-y^2-z^2=xy+xz+yz

E. x^4+y^4+z^4=2xy+2xz+2yz

* A solution will be posted in two days.

In case one does not remembers the formula, plugging smart numbers will be highly effective.

Let \(x=z=1\) & \(y=4\). this satisfies our stem equation. Test the values in the options and the option where \(LHS=RHS\) will be correct

For Option B \(LHS=1^2+4^2+1^2=18\)

\(RHS=2*1*4+2*1*1+2*4*1=18\).

For other options, LHS will not be equal to RHS