Star Operation
Source:
January 11, 2009
Problem Statement
For each pair of real numbers a\not\equal{} b, define the operation as (a \star b) \equal{} \frac{a \plus{} b}{a \minus{} b}. What is the value of ? (A)\ \minus{}\frac{2}{3}\qquad
(B)\ \minus{}\frac{1}{5}\qquad
(C)\ 0\qquad
(D)\ \frac{1}{2}\qquad
(E)\ \text{This value is not defined.}