0=-4.9x^2+39.2x-39.3

Solution for 0=-4.9x^2+39.2x-39.3 equation:

0=-4.9x^2+39.2x-39.3

We move all terms to the left:

0-(-4.9x^2+39.2x-39.3)=0

We add all the numbers together, and all the variables

-(-4.9x^2+39.2x-39.3)=0

We get rid of parentheses

4.9x^2-39.2x+39.3=0

a = 4.9; b = -39.2; c = +39.3;
Δ = b2-4ac
Δ = -39.22-4·4.9·39.3
Δ = 766.36
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{-(-39.2)-\sqrt{766.36}}{2*4.9}=\frac{39.2-\sqrt{766.36}}{9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-39.2)+\sqrt{766.36}}{2*4.9}=\frac{39.2+\sqrt{766.36}}{9.8}
$