Answer:
![f(x)=9((5)/(3) )^x](https://img.qammunity.org/2021/formulas/mathematics/high-school/5o4dbejloj6ad6kcggdyvsg5exuucejyry.png)
Explanation:
We want to solve for a and b. So, let's substitute 0 in for x and 9 in for f(x);
![f(x)=a*b^x](https://img.qammunity.org/2021/formulas/mathematics/high-school/urhr02al86x7162no5thyjak4ub7fl17dk.png)
9 =
![a*b^0=a*1=a](https://img.qammunity.org/2021/formulas/mathematics/high-school/rhiobo5aojzzjihyonjnega56mciopg0l5.png)
So we know that a = 9.
To find b, let's plug 1 in for x and 15 in for f(x) (again, this is from the given table):
![f(x)=a*b^x](https://img.qammunity.org/2021/formulas/mathematics/high-school/urhr02al86x7162no5thyjak4ub7fl17dk.png)
15 = 9 *
![b^1=9*b](https://img.qammunity.org/2021/formulas/mathematics/high-school/iu9fpd4vodjc0gmamych34ke1ukvypvnme.png)
Divide both sides by 9:
b = 15/9 = 5/3
So, our equation for f(x) is:
![f(x)=9((5)/(3) )^x](https://img.qammunity.org/2021/formulas/mathematics/high-school/5o4dbejloj6ad6kcggdyvsg5exuucejyry.png)
Hope this helps!