420*x^2-2x-2=0

Solution for 420*x^2-2x-2=0 equation:

420x^2-2x-2=0

a = 420; b = -2; c = -2;
Δ = b2-4ac
Δ = -22-4·420·(-2)
Δ = 3364
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3364}=58$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-58}{2*420}=\frac{-56}{840}
=-1/15
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+58}{2*420}=\frac{60}{840}
=1/14
$