Hello. I would like recommendations for a couple books. One which covers introductory number theory, algebra - etc(these looked interesting, I'm not sure which would be best but the "fundamental concepts of algebra" looked pretty good on goggle books - http://store.doverpublications.com/0486614700.html http://store.doverpublications.com/0486663418.html http://store.doverpublications.com/048643480x.html) One which gives a fairly indepth look at both trig and geometry And a good linear algebra book.(I looked at these, I'm not sure which would be best - http://store.doverpublications.com/048663518x.html http://store.doverpublications.com/0486660141.html http://store.doverpublications.com/0486635457.html) I have taken calc 1-3 and done some differential equation stuff but, it feels like I could benefit greatly from looking at these subjects, I feel it would solidify my understanding verses just plugging numbers into equations and following instructions on how to solve them. Dover books are preferable due to their greatly reduced price.