Question

If 1/x -1/y =1/z then z=

Answer 1

⇒1/x -1/y =1/z

⇒(y-x)/xy = 1/z

⇒z= xy/(y-x)

Answer 2

$\frac{1}{x} - \frac{1}{y} = \frac{1}{z} \\ \frac{(y - x)}{xy} = \frac{1}{z} \\ z =( \frac{xy}{y - x} )$
I hope this is the answer which you needed .