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

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Answer 1 · 2017-07-04T05:19:05

$x=-4+-sqrt21$

The quadratic formula is $x=[-b+-sqrt(b^2-4ac)]/(2a)$

in your formula $a=1$
$b=8$
and $c=-5$

$x=[-8+-sqrt(8^2-4*1*-5)]/(2*1)$

$x=[-8+-sqrt(64+20)]/2$

$x=[-8+-2sqrt21]/2$

$x=-4+-sqrt21$

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