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Math Help - Inverse of a function

  1. #1
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    Inverse of a function

    Hello - I need help with the following problem. I was asked to find the inverse of: f(x) = 7x+3 over 8

    If Im doing this correctly, I would first replace f(x) with y, then I switched y and x. I believe my next step would be to multiply both sides by 8, correct? So I think that would give me 8x = 56y+24? From here Im stuck because Im forgetting a process Ive already learned. I know I need to get y by itself but how?

    Your help is greatly appreciated.
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  2. #2
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    y = \frac{7x+3}{8}

    swap variables ...

    x = \frac{7y+3}{8}

    multiply both sides by 8 ...

    8x = 7y+3

    solve for y to finish it.
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  3. #3
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    My answer would be 8x-3 over 7 = Y
    ?
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  4. #4
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    so ... how can you check the result?
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