Answer:
4 = a
0 < b <1
Step-by-step explanation:
y = a* b^x
We know that when x=0 y = 4
4 = a * b^0
4 = a * 1
That means a = 4
y = 4 * b^x
We also know that it is decreasing which means b must be between 0 and 1
