-45x2-121x-72=0

Solution for -45x2-121x-72=0 equation:

-45x^2-121x-72=0

a = -45; b = -121; c = -72;
Δ = b2-4ac
Δ = -1212-4·(-45)·(-72)
Δ = 1681
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1681}=41$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-121)-41}{2*-45}=\frac{80}{-90}
=-8/9
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-121)+41}{2*-45}=\frac{162}{-90}
=-1+4/5
$