X^2-20x-9750=0

Solution for X^2-20x-9750=0 equation:

X^2-20X-9750=0

a = 1; b = -20; c = -9750;
Δ = b2-4ac
Δ = -202-4·1·(-9750)
Δ = 39400
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:

$\sqrt{\Delta}=\sqrt{39400}=\sqrt{100*394}=\sqrt{100}*\sqrt{394}=10\sqrt{394}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-20)-10\sqrt{394}}{2*1}=\frac{20-10\sqrt{394}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-20)+10\sqrt{394}}{2*1}=\frac{20+10\sqrt{394}}{2}
$