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  1. #1
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    Question help with fractions

    if 5/n-1/2=3/36, what is the value of n?

    posible answers: -2, 2, 9, 2/7
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  2. #2
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    Quote Originally Posted by lional View Post
    if 5/n-1/2=3/36, what is the value of n?

    posible answers: -2, 2, 9, 2/7

    we can start by reducing the fractions to get

    \frac{5}{n}-\frac{1}{2}=\frac{1}{12}

    The LCD of the equation is 12n so we multiply the whole equation by 12n to get

    \frac{60n}{n}-\frac{12n}{2}=\frac{12n}{12} \iff 60-6n=n

    60=7n \iff n=\frac{60}{7}

    This is not one of your choices but It is correct lets check and make sure.

    So I will plug this into the original equation to get

    \frac{5}{\frac{60}{7}}-\frac{1}{2}\overbrace{=}^{?}\frac{1}{12}

    \frac{35}{60}-\frac{1}{2}\overbrace{=}^{?}=\frac{1}{12}

    Getting a commond denominator I get

    \frac{35}{60}-\frac{30}{60}\overbrace{=}^{?}=\frac{1}{12}

    \frac{5}{60}\overbrace{=}^{?}=\frac{1}{12}

    \frac{1}{12}=\frac{1}{12}

    So the solution checks.

    I hope this helps.
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