9c-15c^2=0

Solution for 9c-15c^2=0 equation:

9c-15c^2=0

a = -15; b = 9; c = 0;
Δ = b2-4ac
Δ = 92-4·(-15)·0
Δ = 81
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{81}=9$
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(9)-9}{2*-15}=\frac{-18}{-30}
=3/5
$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(9)+9}{2*-15}=\frac{0}{-30}
=0
$