60c^2+39c-45=0

Solution for 60c^2+39c-45=0 equation:

60c^2+39c-45=0

a = 60; b = 39; c = -45;
Δ = b2-4ac
Δ = 392-4·60·(-45)
Δ = 12321
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{12321}=111$
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(39)-111}{2*60}=\frac{-150}{120}
=-1+1/4
$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(39)+111}{2*60}=\frac{72}{120}
=3/5
$