0=-4.9(x^2)-19.8(x)+12

Solution for 0=-4.9(x^2)-19.8(x)+12 equation:

0=-4.9(x^2)-19.8(x)+12

We move all terms to the left:

0-(-4.9(x^2)-19.8(x)+12)=0

We add all the numbers together, and all the variables

-(-4.9x^2-19.8x+12)=0

We get rid of parentheses

4.9x^2+19.8x-12=0

a = 4.9; b = 19.8; c = -12;
Δ = b2-4ac
Δ = 19.82-4·4.9·(-12)
Δ = 627.24
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(19.8)-\sqrt{627.24}}{2*4.9}=\frac{-19.8-\sqrt{627.24}}{9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(19.8)+\sqrt{627.24}}{2*4.9}=\frac{-19.8+\sqrt{627.24}}{9.8}
$