-4.9x^2+4.9x+3=0

Solution for -4.9x^2+4.9x+3=0 equation:

-4.9x^2+4.9x+3=0

a = -4.9; b = 4.9; c = +3;
Δ = b2-4ac
Δ = 4.92-4·(-4.9)·3
Δ = 82.81
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4.9)-\sqrt{82.81}}{2*-4.9}=\frac{-4.9-\sqrt{82.81}}{-9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4.9)+\sqrt{82.81}}{2*-4.9}=\frac{-4.9+\sqrt{82.81}}{-9.8}
$