1.2x^2-5.2x+2.8=0

Solution for 1.2x^2-5.2x+2.8=0 equation:

1.2x^2-5.2x+2.8=0

a = 1.2; b = -5.2; c = +2.8;
Δ = b2-4ac
Δ = -5.22-4·1.2·2.8
Δ = 13.6
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{-(-5.2)-\sqrt{13.6}}{2*1.2}=\frac{5.2-\sqrt{13.6}}{2.4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5.2)+\sqrt{13.6}}{2*1.2}=\frac{5.2+\sqrt{13.6}}{2.4}
$