9b^2-6b-80=0

Solution for 9b^2-6b-80=0 equation:

9b^2-6b-80=0

a = 9; b = -6; c = -80;
Δ = b2-4ac
Δ = -62-4·9·(-80)
Δ = 2916
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2916}=54$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-6)-54}{2*9}=\frac{-48}{18}
=-2+2/3
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-6)+54}{2*9}=\frac{60}{18}
=3+1/3
$