17x^2-56x+20=0

Solution for 17x^2-56x+20=0 equation:

17x^2-56x+20=0

a = 17; b = -56; c = +20;
Δ = b2-4ac
Δ = -562-4·17·20
Δ = 1776
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:

$\sqrt{\Delta}=\sqrt{1776}=\sqrt{16*111}=\sqrt{16}*\sqrt{111}=4\sqrt{111}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-56)-4\sqrt{111}}{2*17}=\frac{56-4\sqrt{111}}{34}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-56)+4\sqrt{111}}{2*17}=\frac{56+4\sqrt{111}}{34}
$