Answer:
she will pay 79.36 in taxes
Step-by-step explanation:
Your answer will be twelve and nine thousandths because in place value decimals are like tenths, hundredths, thousandths. In place value for regular numbers are ones, tens, hundreds and so on. So, when you have 12.009, you are going to separate the decimals with the numbers. Then, write down the number in words which would be twelve. Now, go to the decimal and write that down, which is 9 thousandths. Finally, combine the both of them to get: twelve and nine thousandths.
Hope this helps :)
and good luck
A function

is periodic if there is some constant

such that

for all

in the domain of

. Then

is the "period" of

.
Example:
If

, then we have

, and so

is periodic with period

.
It gets a bit more complicated for a function like yours. We're looking for

such that

Expanding on the left, you have

and

It follows that the following must be satisfied:

The first two equations are satisfied whenever

, or more generally, when

and

(i.e. any multiple of 4).
The second two are satisfied whenever

, and more generally when

with

(any multiple of 10/7).
It then follows that all four equations will be satisfied whenever the two sets above intersect. This happens when

is any common multiple of 4 and 10/7. The least positive one would be 20, which means the period for your function is 20.
Let's verify:


More generally, it can be shown that

is periodic with period

.
C, not sure but C. It makes sense to me & I got it right when I did it