3=4.9x^2+x

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

3=4.9x^2+x

We move all terms to the left:

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

We get rid of parentheses

-4.9x^2-x+3=0

We add all the numbers together, and all the variables

-4.9x^2-1x+3=0

a = -4.9; b = -1; c = +3;
Δ = b2-4ac
Δ = -12-4·(-4.9)·3
Δ = 59.8
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{-(-1)-\sqrt{59.8}}{2*-4.9}=\frac{1-\sqrt{59.8}}{-9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+\sqrt{59.8}}{2*-4.9}=\frac{1+\sqrt{59.8}}{-9.8}
$