How do you solve using the quadratic formula 2x^2-6=-x?

1 Answer
Aug 30, 2016

x =3/2 or -2

Explanation:

Rearrange to x^2+x-6=0
This does factorise to (2x-3)(x +2)=0
Giving x =3/2 or -2

The formula for solving the quadratic ax^2+bx+c=0 is

x=(-b+-sqrt(b^2-4ac))/(2a)

Therefore x=(-1+-sqrt(1-(4*2*-6)))/(2*2)

x=(-1+-sqrt(1+48))/4

x=(-1+7)/4 or (-1-7)/4
x=-6/4=-3/2 or x=-8/4=-2