I'm looking into buying a cheap & introductory/mid-level textbooks on Differential Equations and Linear Algebra. My question is, as looking through Apostol's contents for his Multivariable Calculus textbook. I notice sections on DEs as well, would his his text sufficient for those two subjects mentioned above? I plan on purchasing Tenenbaum for ODE and Shilov for Linear Algebra, or would it be better to buy Apostol's and get all 3. Thanks.