8 times of a number is added to its square give a result -15. Then find the number by using its quadratic equation. ​

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8 times of a number is added to its square give a result -15. Then find the number by using its quadratic equation.

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Caroline 8 months 2021-10-07T22:34:26+00:00 2 Answers 0 views 0

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    0
    2021-10-07T22:36:08+00:00

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    8 times of a number is added to its square give a result -15. Then find the number by using its quadratic equations

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    \huge\bold\purple{♡} {\orange{\underline{\blue{\mathbf{AnswEr}}}}} \bold\purple{♡}\\

    Let us consider the given number = x

    Then it’s square = x²

    8 times of it = 8x

    Now adding the above two x² + 8x

    result is = -15

    ⛬ x² + 8x = -15

    ➪ x² + 8x + 15 = 0

    ➪ x² + 5x + 3x + 15 = 0

    ➪ x(x + 3) + 3(x + 5) = 0

    ➪ (x + 3) (x + 5) = 0

    ⛬ x + 3 = 0 or x + 5 = 0

    Then x = -3 or -5

    0
    2021-10-07T22:36:14+00:00

    Answer:

    ANSWER

    Let the number be x

    Given 

    x is added to twice its x2 gives 21

    2×2+x=21

    ⟹2×2+x−21=0

    ⟹2×2+7x−6x−21=0

    ⟹x(2x+7)−3(2x+7)=0

    ⟹(x−3)(2x+7)=0

    ⟹x=3,−27

    The number is 3,−27

    MARK as BRAINLIEST please

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