Can you solve the following equation?

½ = 1/x² + 1/y² +...+ 1/z²

All variables must be different, positive integers, and there must be a finite number of terms.

I know that any positive fraction p/q can be expressed as the sum of reciprocals of finite number

So p/q=1/a+1/b+1/c+.......+1/d(A)

Thus the question is reduced to solve out (A) where

a=x^2,b=y^2,c=z^2,..........d=w^2