ssuming that $x\neq -3$, simplify: $\dfrac{8x-4}{x+3} - \dfrac{12x-20}{2x+6}$

This simplifies to (2x - 7)/(x + 3).

\( \dfrac{8x-4}{x+3} - \dfrac{12x-20}{2x+6}\\ =\dfrac{8x-4}{x+3} - \dfrac{2(6x-10)}{2(x+3)}\\ =\dfrac{8x-4-(6x-10)}{x+3} \\ =\dfrac{8x-4+[-1(6x-10)]}{x+3} \\ \)

You can take it from there, questions are welcome.