How to Solve for X in the Numerator

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When matter and antimatter collide, they disappear. When a number and its multiplicative inverse collide, they also disappear. But this is algebra, not particle physics. You can create the multiplicative inverse, or reciprocal, of a number by writing a fraction with the number in the denominator and 1 in the numerator. The multiplicative inverse of 3, for example, is 1/3. Multiplying 3 by its inverse, therefore, leaves you with 1. This property makes solving for x in a numerator easy.

    Write the equation you wish to solve for x. For example, your write "x/3 = 7."

    Note the number that forms the denominator of the fraction of which x is the numerator. In the example, 3 is the denominator of the fraction.

    Multiply each term in the equation by the number in the denominator. For example, 3 * (x/3) = 3 * 7

    Remember that multiplying any fraction by the term in its denominator eliminates that denominator. For example, 3 * (x/3) = x.

    Simply the left side of your equation using this knowledge. In the example, x = 3 * 7.

    Complete the multiplication on the right side of your equation: x = 21.


About the Author

John Woloch writes professionally for various websites. He has published in the Dutch journal "Crux" and writes frequently on oil painting, classical languages and topics involving math and biochemistry. Woloch holds a Master of Arts in English from the University of Chicago, a Master of Arts in classics from Ohio State University and a postbaccalaureate pre-medical degree from Georgetown University.

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