1. Add and subtract a number or a formula on the left and right sides of the algebraic expression at the same time, and the results are exactly the same.

2. The left and right sides of the algebraic expression are multiplied by a number or a formula at the same time, and the result of the algebraic expression remains unchanged.

3. When the left and right sides of the contemporary number expression are divided by a number that is not 0 at the same time, the result of the algebraic expression remains unchanged.

trait

Algebraic formula is the general name of monomial and polynomial, and it is a part of rational formula. In rational expressions, there can be five operations: addition, subtraction, multiplication, division and multiplication, but in algebraic expressions, the divisor cannot contain letters. Addition and subtraction involve merging similar items. Multiplication and division include basic operations, rules and formulas. Basic operations can be divided into power operations. Rules can be divided into algebra and division, and formulas can be divided into multiplication formula, zero exponential power and negative integer exponential power.