Textbook. 3rd Edition . , overdraft. - M. : Mnemosin, 2008. — 255 s. This tutorial is a continuation of a similar textbook for 8th grade. It almost fully implements the current state program for classes with in-depth study of Mathematics in the main school (including more complex and additional material). The textbook is written in accordance with the general author's concept laid down in textbooks for grades 7, 8 and 9 of general educational institutions .. The book will help the Teacher to organize pre-profile training of schoolchildren who in high school will choose specialized training in mathematics . Inequality with one variable . Systems and Inequalities . Rational inequalities . Multiples and operations on them. Inequality systems . Number of Inequalities . Inequalities with modules. Irrational inequalities . Tasks with parameters. Systems of Equations . Equations with two variables. Inequality with two variables. Basic concepts related to systems of equations and inequalities with two variables. Methods of solving systems of equations . Homogeneous systems . Symmetrical systems. Irrational systems . Systems with modules. Systems of Equations as Mathematical Models of Real Situations . Numerical Functions. Definition of numeric function. Definition area, function value area. Ways to set the function. Function Properties. Even and odd functions. Functions in xn (n is Z), their properties and graphs. Function y ax, its properties and graph. Progression. Numerical Sequences. Properties of Numerical Sequences . Arithmetic progression. Geometric progression. Method of mathematical induction. Elements of combinatorics, statistics and probability theory . Combinatorial tasks. Statistics information design. The simplest probabilistic problems. Experimental data and probability of events.