inverse function

I'll do 12, Nataszaa...the rest use exactly the same process......

12) y=3x+1

First ....get x by itself  by subtracting 1 from both sides

y - 1  = 3x      divide both sides by 3

(y - 1) / 3   = x

Now...."switch" x and y

(x - 1) / 3  = y     now, for "y"...write f^-1(x).....so we have...

f^-1(x) = (x - 1) / 3      ....and that's the inverse function.....

This will really help http://www.mathsisfun.com/sets/function-inverse.html. Read the first few lines. ;) 

I like the picture where you turn it the equation in to a banana. HAve a try, post your answer and someone will let you know if it's correct.

thanks so much again!