Answer:
[tex]y = -3(2^{x})[/tex]
Step-by-step explanation:
y = [tex]kb^{x}[/tex]
Use (0, -3) to find k
[tex]-3 = kb^{0} = k(1) = k\\[/tex]
So, k = -3
Now use (4, -48) to find b
-48 = [tex]-3b^{4}[/tex]
[tex]b^{4}[/tex] = 16
b = 2
Since k = -3 and b = 2, [tex]y = -3(2^{x})[/tex]