Find the equation of the exponential function with yintercep

Find the equation of the exponential function with y-intercept (0,12) and decreases at a rate of 48.5%. Show your work.

Let the general equation of exponential function be :

y = a(b)^x

at x=0 y =12 ; 12 = a(b)^0 ----> a =12

So, y = 12(b)^x

b = 1 - decay rate = 1- 0.485 =0.515

So, y = 12(0.515)^x