Depends on where you plan to go for your undergraduate career, but I would personally retake them if it was your first time with no studying (esp. with math as your lowest score).
Math is one of the easiest to study for, as a lot of it is predictable (know some geometry postulates and some algebra), so it's easy to boost that up to at least a 30 and raise your composite some. Additionally you could study for the other sections and raise those some too. You might've also had bad luck this time around (the inverse is also true), so you'd be surprised what you could score with some experience and rigorous studying under your belt.
I would retake for a higher score for more potential scholarship money, if for no other reason than that.