20x2+10x-8=0

Solution for 20x2+10x-8=0 equation:

20x^2+10x-8=0

a = 20; b = 10; c = -8;
Δ = b2-4ac
Δ = 102-4·20·(-8)
Δ = 740
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{740}=\sqrt{4*185}=\sqrt{4}*\sqrt{185}=2\sqrt{185}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(10)-2\sqrt{185}}{2*20}=\frac{-10-2\sqrt{185}}{40}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+2\sqrt{185}}{2*20}=\frac{-10+2\sqrt{185}}{40}
$