15x^2-26x-80=0

Solution for 15x^2-26x-80=0 equation:

15x^2-26x-80=0

a = 15; b = -26; c = -80;
Δ = b2-4ac
Δ = -262-4·15·(-80)
Δ = 5476
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{5476}=74$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-26)-74}{2*15}=\frac{-48}{30}
=-1+3/5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-26)+74}{2*15}=\frac{100}{30}
=3+1/3
$