X^2-81x+1640=0

Solution for X^2-81x+1640=0 equation:

X^2-81X+1640=0

a = 1; b = -81; c = +1640;
Δ = b2-4ac
Δ = -812-4·1·1640
Δ = 1
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1}=1$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-81)-1}{2*1}=\frac{80}{2}
=40
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-81)+1}{2*1}=\frac{82}{2}
=41
$