The difference of the square of a number and 28 is equal to three times that number find the negative solution

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The difference of the square of a number and 28 is equal to three times that number find the negative solution

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Minh Khuê 3 years 2021-07-29T19:59:44+00:00 1 Answers 9 views 0

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  1. thachthao
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    2021-07-29T20:01:32+00:00
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    Answer:

    The negative solution = x = -4

    Step-by-step explanation:

    Let the number be = x

    The square of number = x²

    The difference between the square of a number and 28 = x²-28

    Given that the difference of the square of a number and 28 is equal to three times that number.

    Thus, the equation becomes

    x^2-28=3x

    subtract 3x from both sides

    x^2-28-3x=3x-3x

    x^2-3x-28=0

    \left(x+4\right)\left(x-7\right)=0

    x+4=0\quad \mathrm{or}\quad \:x-7=0

    x=-4,\:x=7

    Thus, the negative solution = x = -4

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