How do you solve using the quadratic formula $x^2 - 5x - 8 = 0$ ?

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Answer 1 · 2018-07-10T14:19:49

$x_1=5/2pmsqrt(57)/2$

using the formula for

$x^2+px+q=0$
$x_(1,2)=-p/2pmsqrt(p^2/4-q)$
so we get for $p=-5,q=-8$
$x_(1,2)=5/2pmsqrt(25/4+8)$
Note that

$25/4+8=(25+32)/4=57/4$

$x_(1,2)=5/2pmsqrt(57)/2$

How do you solve using the quadratic formula x^2 - 5x - 8 = 0x^2 - 5x - 8 = 0?