Math plz help lol

Question

The graph of an exponential function of the form  contains the points (2, 60) and (4, 240). 

 

What are the values of a and b

Answer 1

(2, 60),(4, 240)

y = ab^x

60= ab^2

240 =ab^4

divide last by 2nd to last equation

4 = b^2

b= 2 or -2

60 = a(4)

a= 60/4 = 15

y =15(2)^x is the exponential equation

or f(x) = 15(2)^x

240 =15(2)^4=15(16)= 240

a=15

b =2