Question

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

Answer 1

Answer:

1/x+2/y=1/z

=>(y+2x)/xy=1/z

Now as xy=z

y+2x=1

=>y=1-2x

The average of x and y is (x+y)/2=(x+1-2x)/2

=(1-x)/2