On a Mac, if one uses Inkscape, one cannot write equations directly (as far as I know). To go around this what I've done is write the equations in LaTeXiT and then import the PDF in Inkscape and then edit the image in Inkscape. When I do this the image decreases in font and quality and does not look as the original, as shown in the image below:
The original one is the left but the right one is the one in Inkscape. Does someone know why the image decreases in quality like that? How does one insert the image normally without changing it?