Question

1/x+1/y=1/z and xy=z what is the average of x and y?

Answer 1

average=(x+y)/2.
Assuming you wanted it in terms of z, then it's
1/y=1-1/x=(x-1)/x
y=x/(x-1)
So (x+x/(x-1))/2=avg=(x^2-x+x)/(2x-2)=x^2/(2x-2)

Answer 2

well, not in terms of z...

Answer 3

(x+y)/xy=1/z
x+y=1
average = 0.5

Answer 4

1/x+1/y=1/z
Solve for y please
Thanks