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Anonymous
Anonymous asked in Science & MathematicsMathematics · 2 years ago

help on this algebra equation?

“solve 2x = x^2 - 8 using the quadratic formula. show all work.”

6 Answers

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  • Como
    Lv 7
    2 years ago

    x² - 2x - 8 = 0

    x = [- b ± √ (b² - 4ac) ] / 2a

    x = [ 2 ± √ (4 + 32) ] / 2

    x = [ 2 ± 6 ] / 2

    x = 4 , - 2

  • DWRead
    Lv 7
    2 years ago

    2x = x² - 8

    x² - 2x - 8 = 0

    quadratic formula:

    x = [-(-2) ± √((-2)² - 4(1)(-8))]/(2(1))

     = [2 ± √36]/2

     = [2 ± 6]/2

     = 4, -2

  • 2 years ago

    2x = x^2 - 8

    x^2 - 2x - 8 = 0

    x

    = [-b +/- (b^2 - 4ac)^(1/2)] / 2a

    = [2 +/- (4 + 32)^(1/2)] / 2

    = 1 +/- 3

    = -2 or 4

  • 2 years ago

    x² – 2x – 8 = 0

    quadratic equation:

    to solve ax² + bx + c = 0

    x = [–b ± √(b²–4ac)] / 2a

    x = [2 ± √(4+32)] / 2

    x = [2 ± √(36)] / 2

    x = [2 ± 6)] / 2

    x = 1 ± 3

    x = 4, –2

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  • 2 years ago

    0 = x^2 - 2x - 8.

    The "a,b,c" of this quadratic are 1, -2, and -8.

    Therefore

    x = -b/2a +/- (1/2a)*sqrt(b^2 - 4ac)

    = 1 +/- (1/2)*sqrt(4+32)

    = 1 +/- 3;

    the solutions are +4 and -2.

  • 2 years ago

    To use quadratic equation, you need your equation in standard form:

    0 = ax² + bx + c

    So to do that, subtract 2x from both sides and put in proper order:

    2x = x² - 8

    0 = x² - 2x - 8

    Now substitute the following values into the equation and simplify:

    a = 1

    b = -2

    c = -8

    x = [ -b ± √(b² - 4ac)] / (2a)

    x = [ -(-2) ± √((-2)² - 4(1)(-8))] / (2 * 1)

    x = [ 2 ± √(4 + 32)] / 2

    x = [ 2 ± √(36)] / 2

    x = (2 ± 6) / 2

    x = -4/2 and 8/2

    x = -2 and 4

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