Efficient ways to study for SAT Math sections?

Which is better : Learn lessons separately like inequalities equations listed in the need to know concepts in the blue book for algebra or just do practice questions for topics?

If you’re trying to learn/review a topic, I don’t really suggest just doing practice questions without a sense of direction. You wouldn’t gain much from reading the solution when it uses a theorem or formula you don’t understand.

Instead, I recommend going topic by topic, making sure you understand everything needed and can explain it clearly to someone else.