If r and y are integers and (15^r + 15^(r+1))/4^y = 15^y what is the value of r?	Choose the most appropriate option
A) 2  B) 3  C) 4  D) 5  E) Cannot be determined
\frac{15^r( 1+ 15)}{4^y} = 15^y   (15^r . 4^2 ) / 4^y = 15^y. 4^0   15^r . 4^(2-y) = 15^y. 4^0   Equating the powers, r = y; 2-y = 0; So r = y = 2=2
<result>A</result>
If r and y are integers and (15^r + 15^(r+1))/4^y = 15^y what is the value of r?