Question 687803
Compare to {{{ax^2 + bx + c = 0}}}
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{{{-x^2 + 7x -8 = 0}}}
a = -1, b = 7, c = -8
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quadratic formula
{{{x=(-b+-sqrt(b^2-4ac))/2a)}}}
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{{{x = (-7 +- sqrt(7^2-4(-1)(-8)))/(2*-1)}}}
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{{{x = (-7 +- sqrt(49 - 32))/-2}}}
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{{{x = (-7 +- sqrt(17))/-2}}}
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{{{x = (-7+sqrt(17))/-2 = -7/-2 + sqrt(17)/-2 = 7/2 - sqrt(17)/2}}}
AND
{{{x = (-7-sqrt(17))/-2 = -7/-2 - sqrt(17)/-2 = 7/2 + sqrt(17)/2}}}
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