PREFACE.
Within a comparatively short time, the algebra requirement for admission to many of our Colleges and Schools of Science has been much increased in both thoroughness of preparation and amount of subject-matter. This increase has made necessary the rearrangement and extension of elementary algebra, and it is for this reason that the present revision of Hall and Knight's Elementary Algebra has been undertaken.
The marked success of the work, and the hearty endorsement by many of our ablest educators of the treatment of the subject as therein presented, warrant the belief that the present edition, with its additional subject-matter, will be found a desirable arrangement and satisfactory treatment "of every part of the subject required for admission to any of our Colleges or Schools of Technology.
Many changes in the original chapters have been made, among which we would call attention to the following: A proof, by mathematical induction, of the binomial theorem for positive integral index has been added to Chapter xxxix.; a method of finding a factor that will rationalize any binomial surd follows the treatment of binomial quadratic surds; Chapter xlii. has been re-written in part, and appears as a chapter on equations in quadratic form; and the chapter
