3=0.00657x^2-0.330x-0.0633

Solution for 3=0.00657x^2-0.330x-0.0633 equation:

3=0.00657x^2-0.330x-0.0633

We move all terms to the left:

3-(0.00657x^2-0.330x-0.0633)=0

We get rid of parentheses

-0.00657x^2+0.330x+0.0633+3=0

We add all the numbers together, and all the variables

-0.00657x^2+0.330x+3.0633=0

a = -0.00657; b = 0.330; c = +3.0633;
Δ = b2-4ac
Δ = 0.3302-4·(-0.00657)·3.0633
Δ = 0.189403524
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{-(0.330)-\sqrt{0.189403524}}{2*-0.00657}=\frac{-0.33-\sqrt{0.189403524}}{-0.01314}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0.330)+\sqrt{0.189403524}}{2*-0.00657}=\frac{-0.33+\sqrt{0.189403524}}{-0.01314}
$