12d^2-72d+60=0

Solution for 12d^2-72d+60=0 equation:

12d^2-72d+60=0

a = 12; b = -72; c = +60;
Δ = b2-4ac
Δ = -722-4·12·60
Δ = 2304
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2304}=48$
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-72)-48}{2*12}=\frac{24}{24}
=1
$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-72)+48}{2*12}=\frac{120}{24}
=5
$