17x2-8x-20=0

Solution for 17x2-8x-20=0 equation:

17x^2-8x-20=0

a = 17; b = -8; c = -20;
Δ = b2-4ac
Δ = -82-4·17·(-20)
Δ = 1424
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:

$\sqrt{\Delta}=\sqrt{1424}=\sqrt{16*89}=\sqrt{16}*\sqrt{89}=4\sqrt{89}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-4\sqrt{89}}{2*17}=\frac{8-4\sqrt{89}}{34}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+4\sqrt{89}}{2*17}=\frac{8+4\sqrt{89}}{34}
$