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Help with differential equations?

I need help solving this differential equation using separation of variables:

ydx + xdy = 3xydx

3 Answers

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  • 10 years ago
    Favourite answer

    Solve this differential equation by separating the variables then integrating:

    y dx + x dy = 3xy dx

    y + x(dy / dx) = 3xy

    x(dy / dx) = 3xy - y

    x(dy / dx) = y(3x - 1)

    dy / y = (3x - 1) / x dx

    dy / y = (3 - 1 / x) dx

    ∫ 1 / y dy = ∫ (3 - 1 / x) dx

    ln|y| = 3x - ln|x| + C

    ln|y| = 3x + C - ln|x|

    y = ℮^(3x + C - ln|x|)

    y = ℮ᶜ℮^(3x) / x

    y = C℮^(3x) / x

  • 10 years ago

    y=x/e^3x

  • 10 years ago

    y=(e^3x)/x

    maybe!!!

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