If you can find one for a reasonable price, get Higher Algebra, a Sequel to Elementary Algebra for Schools by Henry Sinclair Hall and Samuel Ratcliff Knight. It's more than 500 pages and covers many, many topics in algebra that are never taught anymore. There are facsimile reprints available of the 3rd edition which was published in 1889 and reprinted several times in later years. I feel lucky to own a copy.