20x+12=-8x^2

Solution for 20x+12=-8x^2 equation:

20x+12=-8x^2

We move all terms to the left:

20x+12-(-8x^2)=0

We get rid of parentheses

8x^2+20x+12=0

a = 8; b = 20; c = +12;
Δ = b2-4ac
Δ = 202-4·8·12
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{-(20)-4}{2*8}=\frac{-24}{16}
=-1+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+4}{2*8}=\frac{-16}{16}
=-1
$