## anonymous one year ago Need Help please, Medal + Fan: Which equation represents an exponential function that passes through the point (2, 80)? f(x) = 4(x)5 f(x) = 5(x)4 f(x) = 4(5)x f(x) = 5(4)x

1. mathstudent55

Test the point in each equation and see which one works.

2. anonymous

3. mathstudent55

Also, an exponential function has the form $$\large f(x) = ab^x$$ This alone will allow you to eliminate two answers.

4. mathstudent55

An exponential function has x as an exponent. What can you conclude about the first two choices?

5. anonymous

A and B cannot be correct

6. mathstudent55

Good. Now let's look at C and D.

7. anonymous

Okay..

8. mathstudent55

Choice C Is this true? $$80 = 4 \cdot 5^2$$ Choice D Or is this true? $$80 = 5 \cdot 4^2$$

9. anonymous

D

10. anonymous

16x5=80

11. anonymous

Thank you

12. mathstudent55

Correct.