You can contact Mathworks, and ask them. To be honest, the answer is your scheme is probably not legal, since it is essentially fraud. You would be representing yourself as another person, to gain something you do not wish to pay for by normal channels. Viewed in that light, is your plan any different from theft? Hey, its not a lot of money, so it is ok, right? But apparently it is enough money that you are not willing to pay for it yourself, so in your eyes, it is a lot of money.
I'm sorry, but that is what such a fraud means. My guess is you are asking this question because you know inside that it is wrong, and you are hoping someone will tell you to go ahead, that it is ok. But it isn't. Fraud is still fraud, anyway you wrap it.
Do you have alternatives? Certainly. You can use Octave instead, a tool that is actually as close to a MATLAB clone as they could make it, and it is free. Of course, you won't get all of the same tools and toolboxes. Or, you can use Python, or Julia,, etc. There is a lot of stuff written in Python too, so it is a popular choice. There are many free to download computational tools you can use, without perpetrating fraud to obtain them.
Your choice.
