-0.03x^2+0.84x+0.12=0

Solution for -0.03x^2+0.84x+0.12=0 equation:

-0.03x^2+0.84x+0.12=0

a = -0.03; b = 0.84; c = +0.12;
Δ = b2-4ac
Δ = 0.842-4·(-0.03)·0.12
Δ = 0.72
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{-(0.84)-\sqrt{0.72}}{2*-0.03}=\frac{-0.84-\sqrt{0.72}}{-0.06}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0.84)+\sqrt{0.72}}{2*-0.03}=\frac{-0.84+\sqrt{0.72}}{-0.06}
$