What 2 numbers add to get -9 and multiply to get -30?​

Question

What 2 numbers add to get -9 and multiply to get -30?​

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Doris 4 years 2021-08-21T15:57:43+00:00 1 Answers 9 views 0

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  1. Acacia
    0
    2021-08-21T15:59:09+00:00
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    Answer:

    y_{1}=-\frac{9}{2}-\frac{\sqrt{201}}{2} or y_{2}=-\frac{9}{2}+\frac{\sqrt{201}}{2}

    x_{1}=-\frac{9}{2}-\frac{\sqrt{201}}{2} or x_{2}=-\frac{9}{2}+\frac{\sqrt{201}}{2}

    Step-by-step explanation:

    Let be x the first number and y the second number.

    So we have:

    x+y=-9 (1)

    x*y=-30 (2)

    Solve x from equation 1 and put it into equation 2

    x=-9-y

    (-9-y)*y=-30

    -9y-y^{2}=-30

    y^{2}+9y-30=0

    Solving this quadratic equation and put it on the equation (1) the solutions will be:

    y_{1}=-\frac{9}{2}-\frac{\sqrt{201}}{2} or y_{2}=-\frac{9}{2}+\frac{\sqrt{201}}{2}

    x_{1}=-\frac{9}{2}-\frac{\sqrt{201}}{2} or x_{2}=-\frac{9}{2}+\frac{\sqrt{201}}{2}

    I hope it helps you!

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Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )