Write an exponential function y= ab^x for a graph that includes (1,15) and (0,6)

basically you write an exponential function for y=ab^x for a graph that includes (1,15) and (0,6)
then using (0,6) you get: 6 = ab^0 
and using (1,15) you get 15 = ab^1

Equations:
a = 6
ab = 15
So, b = 15/6 = 5/2
Equation:
y = 6(5/2)^x

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