12b^2-28b-80=0

Solution for 12b^2-28b-80=0 equation:

12b^2-28b-80=0

a = 12; b = -28; c = -80;
Δ = b2-4ac
Δ = -282-4·12·(-80)
Δ = 4624
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4624}=68$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-28)-68}{2*12}=\frac{-40}{24}
=-1+2/3
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-28)+68}{2*12}=\frac{96}{24}
=4
$