x+12=3x2

Solution for x+12=3x2 equation:

x+12=3x^2

We move all terms to the left:

x+12-(3x^2)=0

determiningTheFunctionDomain
-3x^2+x+12=0

a = -3; b = 1; c = +12;
Δ = b2-4ac
Δ = 12-4·(-3)·12
Δ = 145
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{145}}{2*-3}=\frac{-1-\sqrt{145}}{-6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+\sqrt{145}}{2*-3}=\frac{-1+\sqrt{145}}{-6}
$