Value of A (algebra)

Question

neeed this asap.

the graph of y = ab^x is decreasing and passes through the point (0,4). What is the value of a?

 

Answer 1

y = ab^x

We can use the point (0,4) to tell us what a is but not b:

y = ab^x
4 = ab⁰
4 = a

 

y = 4b^x