X^2-56x-105=0

Solution for X^2-56x-105=0 equation:

X^2-56X-105=0

a = 1; b = -56; c = -105;
Δ = b2-4ac
Δ = -562-4·1·(-105)
Δ = 3556
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:

$\sqrt{\Delta}=\sqrt{3556}=\sqrt{4*889}=\sqrt{4}*\sqrt{889}=2\sqrt{889}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-56)-2\sqrt{889}}{2*1}=\frac{56-2\sqrt{889}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-56)+2\sqrt{889}}{2*1}=\frac{56+2\sqrt{889}}{2}
$