A, 3x means 3+x B, and x2 means x+x.
C, 3x2 means 3x? 3x D and 3x+5 represent x+x+x+5.
Test site: algebraic expression. Analysis: judge each item according to the meaning expressed by algebraic expressions. Solution: Solution: A, 3x=3? x，
b、x2=x？ x，
c、3x2=3x？ x，
d、3x+5=x+x+x+5。
So choose D. Comments: This topic mainly examines the significance of algebraic expressions, pays attention to clearly expressing the operation order, and understands the difference between power and multiplication.
Question type: multiple-choice hidden analysis experience training collection error correction download test basket 92, (1999? Shanxi) uses language to describe algebraic expressions a2-b2, and the correct one is ().
Square difference of a, a and b, square difference of a and b
The difference between the squares of c, a and b; The difference between the squares of d, b and a.
Test site: algebraic expression. Analysis: It should be described in language according to the order of algebraic expressions. Solution: Solution: a2-b2 is described as the square difference of two numbers A and B in language.
So choose A. Comments: This paper mainly examines the ability to describe algebraic expressions in mathematical language, and notes that a2-b2 represents the square difference of numbers A and B. 。
Question type: multiple-choice hidden analysis experience training collection error correction download test basket 93, algebra ab+ 1 means ()
A, a divided by b plus 1
B, b plus 1 divided by a.
The sum of c, b and 1 is divided by a.
The quotient obtained by dividing d and a by the sum of b and 1
Test site: algebraic expression. Analysis: according to the meaning of algebraic expression, pay attention to the quotient obtained by dividing a by the sum of b and 1 Solution: The algebraic expression ab+ 1 represents the quotient obtained by dividing A by the sum of B and 1.
So you should choose D. Comments: Pay attention to the meaning of algebraic expressions and express the operation process clearly.
Question type: multiple choice questions
a，ba B，a×3 C，3x- 1 d，2 12n。
Test site: algebraic expression. Analysis: judge each item according to the writing requirements of algebraic expression. Answer: Solution: A, correct;
B, the multiplication symbol should be omitted, and the number should be put in front;
C, at the back of the unit should be placed in brackets;
D, with scores should be written as false scores.
So choose A. Note: Writing requirements for algebraic expressions:
The multiplication symbol in (1) algebraic expression is usually abbreviated as "?" Or omit not to write;
(2) When multiplying numbers and letters, the numbers should be written in front of the letters;
(3) The division operation in algebraic expressions is generally written in the form of fractions. Scores should be written in the form of false scores.
Question 2(y-2: Multiple choice questions
A, 2 times y MINUS 2 B, and the product of 2 and y MINUS 2
2 times the difference between c, y and 2; Two times the difference between d and y MINUS two.
Test site: algebraic expression. Analysis: judge each item according to the meaning and operation order of algebraic expressions. Solution: Solution: The correct meaning of algebraic expression 2(y-2) should be twice the difference between Y and 2.
So choose C. Comments: Pay attention to the meaning of algebraic expressions. Answer: Teacher wdxwwzy; Inspection: Mr. HJJ.
Question type: multiple choice questions ☆ ☆ ☆ ☆ ☆ ☆ ☆ Multiple choice questions.
The reciprocal of a, a and b is the square of the difference b, and the difference between a and b is the reciprocal of the square.
The reciprocal of the difference between the squares of c, a and b, the difference between the square of a and the reciprocal of b.
Test site: algebraic expression. Analysis: to say the meaning of algebraic expression is actually to describe algebraic expression in language. When describing, it is required to indicate the order of operation and the final result of operation. Solution: The correct interpretation of algebraic expression a2- 1b is the difference between the square of A and the reciprocal of B. 。
Therefore, choose D. Comments: To express the meaning of algebra in language, we must make clear the various operations contained in algebra and their order. There is no uniform provision for the specific statement, and the starting point is that simplicity does not cause misunderstanding.
Question type: multiple choice questions ☆ ☆ ☆ ☆ ☆ ☆ ☆ Multiple choice questions.
a、5 B、4 C、3 D、2
Test site: algebraic expression. Analysis: According to the concept of algebraic expression, the expression formed by connecting numbers and letters with operational symbols is called algebraic expression. A single number or letter is also an algebraic expression. Solution: There are three algebraic expressions in the problem: -x+ 1, π+3, X-YX+Y * *.
So C. Note: algebraic expressions do not contain ">" and "=".
Question type: multiple choice questions ☆ ☆ ☆ ☆ ☆ ☆ ☆ Multiple choice questions.
a、 12(ab-c) B、 12ab-c C、 12a(b-c) D、 12a( 12b-c)
Test site: algebraic expression. Analysis: This question analyzes the conditions in the question. 12 of A is multiplied by B minus C, and 12 of A is a2. You can write an algebraic expression by multiplying a2 and B-C. Solution: the result can be obtained by analyzing the meaning of the question: 12 of a times the product of b MINUS C.
So the answer is: C. Comments: This question examines the simple definition of algebraic expression, and it is enough to look at the conditions in the question. Question type: multiple-choice questions ☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆ The following is the algebraic expression ()
a、m=ab B 、( a+b)(a-b)=a2-b2
c、a+ 1 D、S=πR2
Test site: algebraic expression. Analysis: the expression formed by connecting numbers and letters with operational symbols is called algebraic expression. A single number or letter is also an algebraic expression. Solution: solution: because the algebraic expression does not contain the "=" sign, it is C.
So C. Note: Algebraic expressions do not contain "=". Answer: Teacher wdxwwzy; Inspection: Mr. HJJ.
Question type: multiple choice questions ☆ ☆ ☆ ☆ ☆ ☆ ☆ Multiple choice questions.
A and -a are negative numbers; B and | A must be non-negative.
C, regardless of the number of a, 1a? A= 1 D and a7 must be fractions.
Test site: algebraic expression. Analysis: judge each item according to the definition and value of algebraic expression and absolute value. Solution: When A is 0, -a is still 0, so A is wrong;
|a| must be a non-negative number, and the correct one is B.
When a=0, there is no reciprocal, so c is wrong;
When a=0, a7 is 0, so D is wrong.
So choose B. Note: The absolute value of any number must be non-negative. Note that letters can represent any real number.
This way, please