Transformations, Algebra Trouble

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SUMMARY

The discussion centers on finding the inverse function of f(x) = (2x + 1) / (x + 2). The correct inverse function is derived as y = (1 - 2x) / (x - 2). Participants clarify the steps involved in rearranging the equation, emphasizing the importance of factoring and isolating y. The final solution is confirmed as correct, demonstrating a clear understanding of algebraic manipulation and inverse functions.

PREREQUISITES
  • Understanding of inverse functions in algebra
  • Familiarity with algebraic manipulation techniques
  • Knowledge of factoring expressions
  • Ability to solve rational equations
NEXT STEPS
  • Study the properties of inverse functions
  • Practice solving rational equations with variable manipulation
  • Learn advanced factoring techniques in algebra
  • Explore applications of inverse functions in real-world scenarios
USEFUL FOR

Students studying algebra, educators teaching inverse functions, and anyone looking to strengthen their skills in algebraic manipulation and problem-solving.

Linday12
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Homework Statement

If f(x)=\frac{2x+1}{x+2}, the equation for y=f^-1(x) is?
So I switch x, x=\frac{2y+1}{y+2}

The Attempt at a Solution


I've tried many ways, but I must be going wrong somewhere, here's what I think to be my nearest:
x(y+2)=2y+1
x(y)+2x=2y+1
x(y)+2x-2x=2y+1-2x
x(y)=2y+1-2x
x(y)-2y=1-2x
And that's as far as I get, it seems I'm stuck in an endless x loop or it simplifies too much to get the correct answer, so I must be missing a vital step or rule.
Sorry, it has been a while since I've done this, and I'm not quite sure if I am even attempting it right. Any tip would be very helpful, I think the answer is:
y=\frac{1-2x}{x-2}

Thank you.
 
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The answer is correct.

x(y)-2y=1-2x
y(x-2)=1-2x
 
Interesting. Let me see if I understand.

x(y)-2y=1-2x <----Am I to factor(not sure if that's the proper word) the left side to get that final answer then, similar to what you showed?

And then I get y(x-2) after the factor
Which then is y(x-2)=1-2x
And then I can get my final answer of:
y=\frac{1-2x}{x-2}

So that is all I was missing? Then it makes sense now. Thank you very much!
 
Yep just factor and then divide by x-2 on both sides.
 

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