0.3x^2-4.5x+12=0

Solution for 0.3x^2-4.5x+12=0 equation:

0.3x^2-4.5x+12=0

a = 0.3; b = -4.5; c = +12;
Δ = b2-4ac
Δ = -4.52-4·0.3·12
Δ = 5.85
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{-(-4.5)-\sqrt{5.85}}{2*0.3}=\frac{4.5-\sqrt{5.85}}{0.6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4.5)+\sqrt{5.85}}{2*0.3}=\frac{4.5+\sqrt{5.85}}{0.6}
$