Answer:

Step-by-step explanation:
We want to write an exponential function that goes through the points (0, 20) and (6, 1280).
The standard exponential function is given by:

The point (0, 20) tells us that <em>y</em> = 20 when <em>x</em> = 0. Hence:

Simplify:

So, our exponential function is now:

Next, the point (6, 1280) tells us that <em>y</em> = 1280 when <em>x</em> = 6. Thus:

Solve for <em>b</em>. Divide both sides by 20:

Therefore:
![b=\sqrt[6]{64}=2](https://tex.z-dn.net/?f=b%3D%5Csqrt%5B6%5D%7B64%7D%3D2)
Hence, our function is:

Answer:
1. 320 2. 580
Step-by-step explanation:
when you round 320, it is 320 because the hundredths place is 0, which is under 5 so the numbers wouldn't change.
When you round 579, the hundredths place is a 9, which is over 5 so you add 1 to seven to get 8.
First you would have to multiply $18 (The cost for each month) and 12 (the number of months in a year) and the answer would be 216
So she deducts 216 a year, so the answer would have to be negative
The final answer is -216