Algebraic Equation

Use the Wolfram-Alpha Theorem to get x=-1/6

https://www.wolframalpha.com/input/?i=3%3D6x%2B4

$\frac{3x+12}{x+4} = \frac{4x^2 + 8x + 8x^2}{2x}\\ \frac{3(x+4)}{x+4} = \frac{12x^2 + 8x }{2x}\\ \frac{3(x+4)}{x+4} = \frac{4x(3x + 2 )}{2x}\\ 3= 2(3x + 2) \\ \frac{3}{2}= 3x + 2 \\ -\frac{1}{2}=3x\\ x=-\frac{1}{6}$