Answer:
f(x) and its inverse are the same
Step-by-step explanation:
<u>The inverse function
</u>
If y=f(x), the inverse function
is defined such as

To find the inverse function, there is a practical method:
a) Change letters x for y and vice-versa
b) Isolate y in terms of x only
c) 
In our case, 
a) Interchanging letters

b) Isolate 
c) 
As we can easily see, f and its inverse are exactly the same

Hope this helps :) see the attachments
You can soustracte the first or the second one
and y cancel
x = 6
now you put 6 in x
you can take the first or the second one
6 - y = -2
6 - y = -2
y = -8