12x+8=-4x2

Solution for 12x+8=-4x2 equation:

12x+8=-4x^2

We move all terms to the left:

12x+8-(-4x^2)=0

We get rid of parentheses

4x^2+12x+8=0

a = 4; b = 12; c = +8;
Δ = b2-4ac
Δ = 122-4·4·8
Δ = 16
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{16}=4$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(12)-4}{2*4}=\frac{-16}{8}
=-2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(12)+4}{2*4}=\frac{-8}{8}
=-1
$