9c^2+24c-20=0

Solution for 9c^2+24c-20=0 equation:

9c^2+24c-20=0

a = 9; b = 24; c = -20;
Δ = b2-4ac
Δ = 242-4·9·(-20)
Δ = 1296
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1296}=36$
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(24)-36}{2*9}=\frac{-60}{18}
=-3+1/3
$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(24)+36}{2*9}=\frac{12}{18}
=2/3
$