18r^2-112r-450=0

Solution for 18r^2-112r-450=0 equation:

18r^2-112r-450=0

a = 18; b = -112; c = -450;
Δ = b2-4ac
Δ = -1122-4·18·(-450)
Δ = 44944
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{44944}=212$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-112)-212}{2*18}=\frac{-100}{36}
=-2+7/9
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-112)+212}{2*18}=\frac{324}{36}
=9
$