Question

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

Answer 1

`x=-4+-sqrt14`

Explanation:

First add `2` to each side so that the equation is in standard form: `y=ax^2+bx+c`.

`x^2+8x+2=0`

The quadratic formula is `(-b+-sqrt(b^2-4ac))/(2a)`.

Here, `a` is `1`, `b` is `8`, and `c` is `2`. Let's plug these numbers into the quadratic formula.

`(-8+-sqrt(8^2-4*1*2))/(2*1)`

`(-8+-sqrt(64-8))/2`

`(-8+-sqrt56)/2`

`(-8+-2sqrt14)/2`

`-4+-sqrt14`

`x=-4+-sqrt14`

Answer 2

`x=-.258, -7.74` Those are averaged btw

Explanation:

first move the two over to the right side
`x^2 +8x +2=0`
Now plug into quadratic formula knowing that a quadratic equation is just `ax^2 +bx +c=0` and the quadratic formula is `x=(-b+-(√b^2-4ac))/(2a)`
`x=(-(8)+-(√(8)^2-4(1)(2)))/(2(1))`
`x=(-8+-(√64-8))/(2)`
`x=(-8+(√56))/2` or `x=(-8-(√56))/2`
Which means `x=-.258, -7.74`