In my math class tests are 70% and homework is 30% so if i wanted at least an 80% how much would be the least percentage i needed in each category

well, if you got 100% on all your tests, that would account for 70% of your grade.

So, you'd then need at least 33.3% on the homework.

But, if you scored 100% on all the homework, that would account for 30% of your grade, so you'd need 71.43% on the tests.

So, the answer to your question depends on the total points scored on the tests and homework.