-4.9x^2-12x+490=0

Solution for -4.9x^2-12x+490=0 equation:

-4.9x^2-12x+490=0

a = -4.9; b = -12; c = +490;
Δ = b2-4ac
Δ = -122-4·(-4.9)·490
Δ = 9748
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:

$\sqrt{\Delta}=\sqrt{9748}=\sqrt{4*2437}=\sqrt{4}*\sqrt{2437}=2\sqrt{2437}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-12)-2\sqrt{2437}}{2*-4.9}=\frac{12-2\sqrt{2437}}{-9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12)+2\sqrt{2437}}{2*-4.9}=\frac{12+2\sqrt{2437}}{-9.8}
$