9y^2+30y-28=0

Solution for 9y^2+30y-28=0 equation:

9y^2+30y-28=0

a = 9; b = 30; c = -28;
Δ = b2-4ac
Δ = 302-4·9·(-28)
Δ = 1908
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1908}=\sqrt{36*53}=\sqrt{36}*\sqrt{53}=6\sqrt{53}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(30)-6\sqrt{53}}{2*9}=\frac{-30-6\sqrt{53}}{18}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(30)+6\sqrt{53}}{2*9}=\frac{-30+6\sqrt{53}}{18}
$