1, algebraic expression
An algebraic expression is an algebraic expression if there are no letters in the denominator.
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.
Step 2 score
If the denominator of an algebraic expression contains letters, it is a fraction.
Generally speaking, if A and B(B is not equal to zero) represent two algebraic expressions, and B contains letters, then the formula A/B is called a fraction, where A is called a numerator and B is called a denominator. Fraction is an algebraic expression different from algebraic expression, and its value changes with the change of letter value in fraction.
Extended data:
1. Algebraic expression algorithm.
1, addition and subtraction rules:
The addition and subtraction of monomial is to merge similar items, that is, the sum of the coefficients of similar items before the merger, and the letters remain unchanged.
For example: 3a+4a=7a, 9a-2a=7a and so on.
At the same time, it should also apply to the rules of removing brackets and adding brackets.
2, the multiplication rule:
The multiplication of monomials is to multiply their coefficients with the same letters respectively. For letters contained only in the monomial, they are used as a factor of the product together with its index.
For example: 3a×4a= 12a?
3, division rules:
The same base power (power) division, base constant, exponential subtraction.
Second, the fractional condition.
1, the condition that the score is meaningful: the denominator is not 0.
2. The condition that the fractional value is 0: the numerator is 0 and the denominator is not 0.
3. The condition that the fractional value is positive (negative): the same sign of the numerator and denominator is positive, and the different sign is negative.
4. Condition of fractional value 1: numerator = denominator ≠0.
5. The condition that the fractional value is-1: both the numerator and denominator are reciprocal, and neither is 0.
Baidu encyclopedia-algebraic expression
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