-3x^2-17x+72=0

Solution for -3x^2-17x+72=0 equation:

-3x^2-17x+72=0

a = -3; b = -17; c = +72;
Δ = b2-4ac
Δ = -172-4·(-3)·72
Δ = 1153
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{-(-17)-\sqrt{1153}}{2*-3}=\frac{17-\sqrt{1153}}{-6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-17)+\sqrt{1153}}{2*-3}=\frac{17+\sqrt{1153}}{-6}
$