https://essaysnark.blocked/2010/06/ ... -gmat.html
https://essaysnark.blocked/2011/05/ ... -gmat.html
The fact that you did well in those other classes might even make the adcom think you have no excuses, that you should do better on the test! So no, those courses don't offset a low quant.
What we typically see when people try to write an optional essay around a poor GMAT score is just a bunch of hemming and hawing about how the test "does not refect my potential" yada yada yada... basically, excuses. There are only a few reasons that seem adequate to present that could actually EXPLAIN the score. And that's what the optional essay should be used for: EXPLANATIONS. It should never be written unless there's something meaningful that can be added to the adcom's understanding of your profile, that you're not able to fit in elsewhere.
Unfortunately our very depressing advice is, if your GMAT score is really low, then the best way you can help yourself is to take the darn test again.
If you do decide to write an optional essay despite all our advice against it
then it should be as short as humanly possible (some schools have actual length limits, sometimes as short as ~250 words) and you need to offer something concrete. Not sure if you'll find this to be helpful, but it's our best advice.
EssaySnark
