the quadratic formula for 5x^2+33x+40?

im stuck on cognitive tutor ;-;

3 Answers

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  • 8 years ago
    Favorite Answer

    5x^2 +33x = -40

    DIVIDE BY 5

    x^2 + 33/5x = -8

    ADD 1089/100

    x^2 + 33/5x +1089/100 = 1089/100 -8 = 289/100

    ( x + 33/10 )^2 = 289/100

    x = 1/10 ( -33 +17) OR 1/10 ( -33 -17)

    x = -8/5 OR -5 ANSWER

  • Niall
    Lv 7
    8 years ago

    x = [-b ± √b² - 4ac]/2a

    x = [-33 ± √(33)^2 - 4(5)(40)] / (2)(5)

    x = [-33 ± √1089 - 800] / 10

    x = [-33 ± √289] / 10

    x = [-33 ± 17] / 10

    Now solve for each:

    x = -16/10 (simplifies to -8/5)

    x = -50/10 (simplifies to -5)

    x = -5, -8/5

  • 8 years ago

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

    x = [-33+/-sqrt(33^2 - 4(5)(40))]/2(5)

    x = [-33+/-sqrt(1089-800)]/10

    x = [-33+/-sqrt(289]/10

    x = (-33 +/- 17)/10

    x = (-33+17)/10, (-33-17)/10

    x = -16/10, -5

    x = -1 3/5, -5

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