3r^2-60=3r

Solution for 3r^2-60=3r equation:

3r^2-60=3r

We move all terms to the left:

3r^2-60-(3r)=0

a = 3; b = -3; c = -60;
Δ = b2-4ac
Δ = -32-4·3·(-60)
Δ = 729
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{729}=27$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-3)-27}{2*3}=\frac{-24}{6}
=-4
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3)+27}{2*3}=\frac{30}{6}
=5
$