3=-0.3x^2+3.6x-6

Solution for 3=-0.3x^2+3.6x-6 equation:

3=-0.3x^2+3.6x-6

We move all terms to the left:

3-(-0.3x^2+3.6x-6)=0

We get rid of parentheses

0.3x^2-3.6x+6+3=0

We add all the numbers together, and all the variables

0.3x^2-3.6x+9=0

a = 0.3; b = -3.6; c = +9;
Δ = b2-4ac
Δ = -3.62-4·0.3·9
Δ = 2.16
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-3.6)-\sqrt{2.16}}{2*0.3}=\frac{3.6-\sqrt{2.16}}{0.6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3.6)+\sqrt{2.16}}{2*0.3}=\frac{3.6+\sqrt{2.16}}{0.6}
$