Inequality: A formula connected by unequal numbers is called inequality.

Solution of inequality: the value of the unknown that can make inequality hold is called the solution of inequality.

Solving inequality: the process of finding the solution set of inequality

One-dimensional linear inequality; There is only one unknown, and the highest degree of the unknown is an inequality.

One-dimensional linear inequality group: several one-dimensional linear inequalities about the same unknown quantity are combined to form a one-dimensional linear inequality group.

Solution set of linear inequality group: the common part of the solution set of each inequality in linear inequality group.

Solving inequality groups: the process of solving a set of spherical inequality groups.

Chapter II Factorization

Factorization; Convert a polynomial into the product of several algebraic expressions.

The way to improve the common factor is to improve the common factor of a polynomial, so that the polynomial can be transformed into the product of two factors. This method of decomposing factors is called the improved common factor method.

Using formula method: the method of decomposing some polynomials in turn by open multiplication.

Chapter III Scores

Fraction: algebraic expression A is divided by algebraic expression B. If the division B contains letters, then A/B is called algebraic expression.

Fraction reduction: The common factor of the numerator and denominator of a fraction is reduced.

General division of fractions: According to the basic properties of fractions, fractions with different denominators can be converted into fractions with the same denominator, which is called general division of fractions.

Fractional equation: An equation with unknowns in the denominator

Chapter IV Similar Figures

Line segment ratio: If two line segments AB and CD are measured in the same length unit, the length of each line segment is M and N, then the ratio of these two line segments AB: CD = M: N..

Proportional line segment: among the four line segments A, B, C and D, if the ratio of A and B is equal to the ratio of C and D, that is, a/b=c/d, then the four line segments A, B, C and D are called proportional line segments, which are called proportional line segments for short.

Golden section: Point C divides line AB into AC and BC. If AC/AB=BC/AC, the line segment AB is called the golden section of point C..

Similar polygons: each corner corresponds to the same, and each side corresponds to two polygons in proportion.

Similar triangles: Triangle corresponds to equality, and three sides correspond to two triangles to form a proportion.

Chapter V Data Collection and Processing

Census: A comprehensive survey of the respondents.

Population: All the respondents.

Individuals: each of the respondents who make up the whole population.

Sampling survey: select some individuals from the population to investigate.

Frequency: The number of times each object appears.

Frequency: the ratio of the number of times each object appears to the total number of times.

Chapter VI Proof (1)

Proposition: a sentence that judges one thing

Axiom: a recognized true proposition

Theorem: the true proposition of proof

Inference: a theorem directly derived from an axiom or theorem