Which are the solutions of x2 = –5x + 8?

Question

Which are the solutions of x2 = –5x + 8?

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Anna 3 weeks 2022-01-03T13:05:00+00:00 2 Answers 0 views 0

Answers ( )

    0
    2022-01-03T13:06:15+00:00

    Answer:

    A

    Step-by-step explanation:

    e2020 baby

    0
    2022-01-03T13:06:44+00:00

    Answer:

    As exact answers:

    x=\frac{-5-\sqrt{57} }{2}  and  x=\frac{-5+\sqrt{57} }{2}

    As decimal answers:

    x = -6.2749172 ≈-6.3

    x = 1.27491722 ≈  1.3

    Step-by-step explanation:

    For quadratic equations, you can use the quadratic formula. Rearrange the equation to standard from, which is ax² + bx + c = 0.

    x² = –5x + 8

    x² + 5x – 8 = 0

    State the values for “a”, “b” and “c”,

    a = 1; b = 5; c = -8

    x=\frac{-b±\sqrt{b^{2}-4ac} }{2a}            (Ignore the Â, it’s a formatting error)

    x=\frac{-5±\sqrt{5^{2}-4(1)(-8)} }{2(1)}           Simplify

    x=\frac{-5±\sqrt{25-(-32)} }{2}               Two negatives make a positive

    x=\frac{-5±\sqrt{57} }{2}  

    Split the equation at the ± for plus and minus:

    x=\frac{-5+\sqrt{57} }{2}  = 1.27491722 ≈ 1.3

    x=\frac{-5-\sqrt{57} }{2}  = -6.2749172 ≈ -6.3

    Therefore the solutions are 1.3 and -6.3.

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