-15x^2+14x+8=0

Solution for -15x^2+14x+8=0 equation:

-15x^2+14x+8=0

a = -15; b = 14; c = +8;
Δ = b2-4ac
Δ = 142-4·(-15)·8
Δ = 676
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{676}=26$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(14)-26}{2*-15}=\frac{-40}{-30}
=1+1/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(14)+26}{2*-15}=\frac{12}{-30}
=-2/5
$