MathDB
Solving for a Variable

Source:

June 13, 2009

Problem Statement

If \frac {1}{x} \minus{} \frac {1}{y} \equal{} \frac {1}{z}, then z z equals: (A)\ y \minus{} x\qquad (B)\ x \minus{} y\qquad (C)\ \frac {y \minus{} x}{xy}\qquad (D)\ \frac {xy}{y \minus{} x}\qquad (E)\ \frac {xy}{x \minus{} y}