I’ve heard top colleges like 1 math, 1 science, 1 arts/social studies, but my subject scores were 790 math II 780 bio 720 us history 710 Chem. Is it ok to just send bio and math or should I also send us history ?
Read the web sites carefully and see what they require. If there is nothing specific mentioned then go ahead and just send the best scores.
For the relatively few colleges that recommend/require subject tests, they all (except Georgetown) only ask for 2 (unless there are extenuating circumstances, like being homeschooled). No college expects you to read the tea leaves. If a college specifically wanted a math and a science, or a STEM and a humanities, they would say so.
So unless the college requires all scores, send the best 2.