Retaking Subject Tests/Score Choice

<p>Do the same rules about score choice for SAT I apply for subject test. If so I got a 750 on Math and 720 on Bio, and these, to be honest are fairly low percentiles. Does it look bad if I retake them and improve. The main reason I want to retake them is because I know that I should have studied more precalc stuff for math, and in general more for bio.
thanks!</p>