If and are variables satisfying the equation

MATHEMATICS · Single correct · AP · AP Precalculus · Polynomial and Rational Functions · Polynomial and Rational Functions

Problem

r

and

s

are variables satisfying the equation

\frac{1}{r+s} = \frac{1}{r} + \frac{1}{s}

. The value of

\left(\frac{r}{s}\right)^3

is equal to : (a) 1 (b) -1 (c) 3 (d) not possible to determine