.000191-0.042x=3x^2

Solution for .000191-0.042x=3x^2 equation:

.000191-0.042x=3x^2

We move all terms to the left:

.000191-0.042x-(3x^2)=0

determiningTheFunctionDomain
-3x^2-0.042x+.000191=0

We add all the numbers together, and all the variables

-3x^2-0.042x+0.000191=0

a = -3; b = -0.042; c = +0.000191;
Δ = b2-4ac
Δ = -0.0422-4·(-3)·0.000191
Δ = 0.004056
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{-(-0.042)-\sqrt{0.004056}}{2*-3}=\frac{0.042-\sqrt{0.004056}}{-6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-0.042)+\sqrt{0.004056}}{2*-3}=\frac{0.042+\sqrt{0.004056}}{-6}
$