Question

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

Answer 1

`x=-4+-sqrt21`

Explanation:

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`