30 Point Question! I will mark the brainiest if answer!

Exponential function has the form y=ab^x, when x=1, y=7.5, so ab=7.5, equation1
When x=3, y=ab^3=16.875, equation 2
Let a=7.5/b, plug it in equation 2, y=7.5b^2=16.875, b=1.5
So a=7.5/1.5=5
So y=5*1.5^x