I know this thread is old, but… If you’re still in high school, I’d be a little wary about taking linear algebra online. I took linear algebra face-to-face using one of the “mainstream” textbooks out there today and it was one of the biggest shocks I’ve ever had in a math class. I’ve taken lots of math too. I was top of every single one of my math classes. I’d say the shock came from the logic required to function in that class. It wasn’t the systems of equations and matrices that got me. It was all of the proofs. Coming out of the class, all of the proofs actually are quite obvious at this point. But if you’re working through it all first-time, those proofs are going to REALLY take a bite out of you. They require some creative thinking. Thinking you’ve never done before.