2x^2+6x-28=-2x^2

Solution for 2x^2+6x-28=-2x^2 equation:

2x^2+6x-28=-2x^2

We move all terms to the left:

2x^2+6x-28-(-2x^2)=0

We get rid of parentheses

2x^2+2x^2+6x-28=0

We add all the numbers together, and all the variables

4x^2+6x-28=0

a = 4; b = 6; c = -28;
Δ = b2-4ac
Δ = 62-4·4·(-28)
Δ = 484
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{484}=22$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6)-22}{2*4}=\frac{-28}{8}
=-3+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+22}{2*4}=\frac{16}{8}
=2
$