The value, y, of a $15,000 investment over x years is represented by the equation y=15000(1.2)(x/3). what is the profit (interest) on a 6 year investment?
The interest is
Final value - Amount invested =
15000 (1.2)(6/3) - 15000 =
15000 (1.2)(2) - 15000 =
15000 (2.4 - 1) =
15000 (1.4) =
$21000
+470 
