9k^2+30k-25=0

Solution for 9k^2+30k-25=0 equation:

9k^2+30k-25=0

a = 9; b = 30; c = -25;
Δ = b2-4ac
Δ = 302-4·9·(-25)
Δ = 1800
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1800}=\sqrt{900*2}=\sqrt{900}*\sqrt{2}=30\sqrt{2}$
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(30)-30\sqrt{2}}{2*9}=\frac{-30-30\sqrt{2}}{18}
$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(30)+30\sqrt{2}}{2*9}=\frac{-30+30\sqrt{2}}{18}
$