x^2-x-1640=0

Solution for x^2-x-1640=0 equation:

x^2-x-1640=0

We add all the numbers together, and all the variables

x^2-1x-1640=0

a = 1; b = -1; c = -1640;
Δ = b2-4ac
Δ = -12-4·1·(-1640)
Δ = 6561
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{6561}=81$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-81}{2*1}=\frac{-80}{2}
=-40
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+81}{2*1}=\frac{82}{2}
=41
$