Name:
Category:
First, multiple-choice questions (3 points for each question, ***30 points)
1, if the east is positive, then-8m means (
)
Go 8 meters east.
B, walk 8m c to the south, 8m d to the west and 8m to the north.
2. The algebraic expression (a-b)2/c means (
)
The square of the difference between a, a and b is divided by C.
The difference between the squares of b, a and b divided by C.
The square of the difference between c, a and b divided by c D, the difference between the squares of a and b divided by C.
3, zero is ()
A, positive number b, odd number c, negative number d, even number
4. Add a "-"sign before the number to get a ().
I. Negative numbers
B, arbitrary number c, reciprocal d of the original number and a non-positive number
5. If ab=0, then there must be ().
a、a=b=0
B a=0
C
At least one of a and b is 0.
At least one of D a, b and b is 0.
6, the following figures are negative (
)
a 、-(- 1/2) B -|- 1/3|
c-[+(- 1/5)]
D |- 1/6|
7, the following statement is correct ()
(1) The sum of a number and its absolute value cannot be negative. (2) A number subtracts its inverse, and their difference is twice that of the original number; (3) Zero minus a number must be negative. (4) The positive number of burden reduction must be negative. (5) rational number addition and subtraction, the result must still be rational number.
Answer, 2
b，3
c，4
d，5
8. The following figures are correct (
)
a、—(-0.2)=+(+ 1/5)
b 、(-3)+(+3)=6
c 、+(- 1)=-(- 1)
d 、-[+(-7)]=+[-(+7)]
9, the following statement, the correct is (
)
A, there is a minimum rational number
B, there is a maximum negative integer.
C, with the largest negative integer.
D, with the smallest integer.
10. If the quotient of the absolute value of a number divided by a is-1, then a must be (
)
a 、- 1
B, 1 or-1
C, negative number
D, positive number
Second, fill in the blanks. (3 points for each question, ***30 points)
1 1. There are students A, B and C in the classroom, and then there are students (
) people.
12. It is known that the product of two numbers is 36. If a number is m, the sum of these two numbers is (
)
13，x=(
), the algebraic expression (x-4)/3 is equal to 0.
14, after the temperature drops from a. C to t.C, it is (
)
15, let the number a be x and the number b be y, then "the product of two numbers a and b minus the difference between two numbers a and b" can be expressed as (
)
16, if a>0, then | a |= (
)
17, 1293400000 is expressed as (
), the valid number of 89765 is (
), if retained to two significant figures (
)。
18, the number 5 less than -3 is (
)
Third, the calculation problem. (4 points for each question, * * * 16 points)
( 19) {0.85-[ 12+4(3- 10)]}/5 (20)[(-3)3-(-5)3]/[(-3)-(-5)]
(2 1)(-2)3*5-(-0.28)/(-2)2
(22)( 1/4+ 1/6- 1/2)*48
Fourth, answer questions. (6 points for each question, ***24 points)
23. It is known that | a |=5, |b| =3, and the symbols of a and b are different. Find the value of algebraic formula (a+b)(a-b).
24. On the number axis, all integers whose absolute values are not greater than 5 are represented.
25. The weights of five bags of wheat are 183kg, 176kg, 185kg, 178kg, 18 1kg respectively. The excess kilograms are positive, and the shortage kilograms are negative. So how many kilograms do these five bags of wheat exceed or fall short of the standard weight? What is the total weight of these five bags of wheat?
26. During the holidays, the school organizes students to participate in work-study programs for a period of time, and each student receives financial support from 15 yuan. During the activity, some students bought a meal, and the meal fee was deducted 15 yuan. The actual meal fees and amounts received by students are as follows:
(1) Write the formula of c with n (a natural number with n less than or equal to 25).
(2) Calculate what C is when n=6.
The number of meals n The meals are as follows (yuan, money, c (yuan
1.60 yuan 15-0.60= 14.4.
2 1.20 yuan15-1.20 =13.80.
3 1.80 yuan15-1.80 =13.20.
4 2.40 yuan 15-2.40= 12.60
……… ……… ………
Fourth, additional questions. (20 points)
1, a.b is reciprocal, c and d are reciprocal, |m|=3. Find the value of m+cd-(a+b)/(a+b+c).