3r^2-58r-180=0

Solution for 3r^2-58r-180=0 equation:

3r^2-58r-180=0

a = 3; b = -58; c = -180;
Δ = b2-4ac
Δ = -582-4·3·(-180)
Δ = 5524
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{5524}=\sqrt{4*1381}=\sqrt{4}*\sqrt{1381}=2\sqrt{1381}$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-58)-2\sqrt{1381}}{2*3}=\frac{58-2\sqrt{1381}}{6}
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-58)+2\sqrt{1381}}{2*3}=\frac{58+2\sqrt{1381}}{6}
$