How do you find all points of inflection given y=-(2x)/(x+3)?

I may have gone wrong with this one but when I differentiated this and put $\frac{\mathrm{dy}}{\mathrm{dx}} = 0$, I got a quadratic which didn't factorise. I checked online with a graph plotter and the gradient of this graph has asymptotes so am I right in thinking there are no points of inflection?