Option D:

Solution:
Given function:

To find the inverse of the function.
<u>Inverse of a function:</u>
<em>If a function f(x) is mapping x to y, then the inverse function of f(x) maps y back to x.</em>

Interchange the variables x and y.

Now, solve for y.
Multiply both sides by (y - 5).

Cancel the common factors, we get

Divide by x on both sides.

Add 5 on both sides.


To make the denominator same, multiply the 2nd term by
.



Option D is the correct answer.
You want to do to one side the same thing you do to the other side.
In order to get the n by itself you divide the 25n by 25. But in order to not change the answer you need to do the same to the 70.

so n=

which can be reduced to

so n=
If looking for the answer it would be 0, 3, -6, 7
Q.q i dunno , seems like he doesnt have enough money with the 6 deposites of 35.5 = 213 if you add the deposists to 420+213=633 , and he needs 4 checks of 310 eaach , he could only write 2 checks , so i suppose theirs not enough information to accumulate a answer