x^2-4x-340=0

Solution for x^2-4x-340=0 equation:

x^2-4x-340=0

a = 1; b = -4; c = -340;
Δ = b2-4ac
Δ = -42-4·1·(-340)
Δ = 1376
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:

$\sqrt{\Delta}=\sqrt{1376}=\sqrt{16*86}=\sqrt{16}*\sqrt{86}=4\sqrt{86}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-4)-4\sqrt{86}}{2*1}=\frac{4-4\sqrt{86}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4)+4\sqrt{86}}{2*1}=\frac{4+4\sqrt{86}}{2}
$