# I have a final

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Hey I have a final tomarrow, and Iam good with pretty much everything else except finding the inverse of functions especially when the function looks like this f(x) = x - 4 / x - 7 i try to do it but then I will still have either x or y on both sides. Can anyone help me out?

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Hey TempHolder. I don't want to give you the answer, but you may be making this harder than it really is. Remember that you can pull variables out of one side of the equation as long as the variable is a coefficient in every term, like this:

-7y+4 = x - xy;
-7y+4 = x(1-y);

If a mod doesn't have a problem with it, I'd be happy to go into more detail...but as this is quasi-homework, you should keep plugging away at it!

Best of luck on your final!
Aviosity

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thats the thing I get it up to this

y(x - 7) = x - 4,

but x or y would still be on both sides of the equations :-( I need help

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In addition to what aviosity said, don't forget that you are allowed - and almost always required - to multiply out the terms as well as take them out.

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basically what they tell me to do is solve for x in terms of why but after fallowing my steps

y(x - 7) = x - 4,

I will devide the y out and add 7 to the end and ill get

x = (x-4)/y + 7

and I know for a fact that that isnt the answer

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*gets frustrated*

and remember............... you can add and subtract shit too.

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Expand all the terms (do all the multiplications), put all the terms that have "x" on one side and all the terms that don't have "x" on the other side. Factor out the "x". Pass the things that are multiplying x dividing to the other side. Now you have your inverse.

I think we learned this in sixth grade.

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they're right. it's easy. lol. i even got it.

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Quote:
 Original post by Alpha_ProgDesthey're right. it's easy. lol. i even got it.

Seconded. And I'm agnostic to functions [lol].

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Can someone guide me through the steps one by one until we get to the final answer, cause the important thing is that I get the concepts PLEASE someone help.

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