3x^2+31x-9.3=0

Solution for 3x^2+31x-9.3=0 equation:

3x^2+31x-9.3=0

a = 3; b = 31; c = -9.3;
Δ = b2-4ac
Δ = 312-4·3·(-9.3)
Δ = 1072.6
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{-(31)-\sqrt{1072.6}}{2*3}=\frac{-31-\sqrt{1072.6}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(31)+\sqrt{1072.6}}{2*3}=\frac{-31+\sqrt{1072.6}}{6}
$