2005x－2007y＝2003 2004x－2006y＝2002 x. How much y

2005x－2007y＝2003 2004x－2006y＝2002 x. How much y

①2005x—2007y=2003
②2004x—2006y=2002
① - 2, X-Y = 1
X=1+Y
Bring in ① or ②
2005+2005Y-2007Y=2003
2=2Y
Y=1
x=1+y=2

I'm from Beijing No.8 Middle School. We're going to use the same test paper as No.8 Middle School. Please give me some math exercises in 1-2 chapters, I'm a rookie!

Name of mathematics test question in junior high school:
1、 Single choice (3 points for each question, 30 points in total)
1. The cube of a number is equal to itself. The number is ()
A、0 B、1 C、－1,1 D、－1,1,0
2. In the following formulas, the unequal is ()
A. (- 3) 2 and - 32 b, (- 3) 2 and 32 c, (- 2) 3 and - 23 D, - 2 | 3 and - 23|
3、(－1)200＋(－1)201＝( )
A、0 B、1 C、2 D、－2
4. There is a group of numbers: - 1,1 / 2, - 1 / 3,1 / 4, - 1 / 5,1 / 6 Find the law and get the seventh number is ()
A、－1/7 B、1/7 C、－7 D、7
5. The following statement is correct: a. the absolute value of a rational number must be a positive number
B. If the absolute values of two numbers are equal, the two numbers are equal
C. If a number is negative, the absolute value of the number is its opposite
D. The greater the absolute value, the larger the number
6. Comparing the size of - 1 / 5 and - 1 / 6, the result is ()
A. B, < C, = D, uncertain
7. What is wrong in the following statement is ()
A. Zero divided by any number is zero. The absolute value of the reciprocal of B, - 7 / 9 is 9 / 7
C. On the contrary, the number equal to itself is zero and all positive numbers
D. Divide by a number is equal to multiply by its reciprocal
8. (- M) 101 > 0, then there must be ()
A. M > 0 B, m < 0 C, M = 0 d, none of the above are correct
9. When a positive integer n is compared with its reciprocal 1 / N and its opposite number - N, the correct result is ()
A、－n≤n≤1/n B、－n＜1/n＜n
C、1/n＜n＜－n D、－n＜1/n≤n
2、 Fill in the blanks with 3 points for each sub question, 30 points in total)
1. The sum of the opposite number of 12 and the absolute value of - 7 is____________________ .
2. The temperature in the morning is - 5 ℃, which increases by 10 ℃ at noon and decreases by 8 ℃ in the middle of the night__________________ .
3. On the number axis, the distance between - 4 and - 6 is____________________ .
4. If a = 6, B = - 2, C = - 4, and A-B + (- C) - (- D) = 1, then the value of D is__________ .
5. If 50% of a number is - 5.85, then this number is_________________ .
6. If the square of a number equals 81, then this number is____________________ .
7. If | a | = 2.3, then a =__________________________ .
8. Calculation - | - 6 / 7| =___________________ .
9. All numbers with absolute values greater than 2 but less than 5 are____________________ .
10. There is a column of numbers. Observe the rule and fill in the following numbers, - 5, - 2,1,4_______ ,________ ,________ .
3、 Calculation questions (5 points for each sub question, 20 points in total)
1、－15＋6÷(－3)×1/2 2、(1/4－1/2＋1/6)×24
3、|－5/14|×(－3/7)2÷3/14 4、2/3＋(－1/5)－1＋1/3
4、 Answer questions (10 points for each sub question, 20 points in total)
1. According to the meteorological observation data of a sounding balloon, the temperature will decrease by 6 ℃ for every 1 km increase in altitude. If the ground temperature is 21 ℃ and the temperature in the upper air is - 39 ℃, how many kilometers is the altitude here?
2. The weight of 10 students was measured on the basis of 50 kg. The excess was recorded as positive and the insufficient was recorded as negative. The results were as follows (unit: kg) 2,3, - 7.5, - 3,5, - 8,3.5,4.5,8, - 1.5
What is the total weight of these 10 students? What is the average weight?
Final math test for Grade 7 (1)
Class name score______
1、 Fill in it patiently (3 points for each question, 30 points in total)
1. (1) the opposite of 1.4 is; (2) the reciprocal of (2) is; (3) - =
2. If known, then - nm =
If n =, then the equation is linear
4. As shown in the graph, it is an expanded graph of a cube. If the numbers on the opposite sides of the cube are opposite to each other, then a - (B-C) =
5. Extend the segment AB to C so that BC = AB, and reverse extend AC to D to make ad = AC. if AB = 8cm, then CD =
Add another 15 lines to the line segment AB to make it possible to add 6 points to ab
7. The qualified rate of a batch of parts is checked by the quality inspector. The specified size of the parts is 30 ± 0.5cm. Now 10 parts are sampled and the inspection results are: 30.3,30.0,30.4,29.4,30.2,29.8,30.6,29.5,30.5 (unit: cm), then the qualified rate of this batch of parts is
8. The daily turnover of a shopping mall during the "October 1" holiday is 150000 yuan. From this, the total turnover in October is about 15 × 31 = 4650000 yuan. Do you think such a calculation is reasonable
9. If ∠ AOB = 50 ° and ∠ BOC = 30 ° are known, then ∠ AOC =
10. In order to teach tomorrow spring, please give some suggestions to the math teacher according to the problems in the teaching this autumn
2、 If you choose carefully, you will know gold well (2 points × 8 = 16 points)
11. - 22 and (- 2) 2 ()
A. The product of them is 16
12. Given the position of rational numbers a and B on the number axis as shown in the figure, then the size relationship between a, - A, B, - B is ()
A.-a＜-b＜a＜b
B. a＜-b＜b＜-a
C.-b＜a＜-a＜b
D.a＜b＜-b＜-a
Xiao Ming wants to know about how many stars there are in the galaxy
A. Questionnaire survey B. field investigation C. literature review D. experiment
14. The significant figure of the approximate value of 0.06097 to the thousandth place by rounding is ()
A.0、6、0 B.0、6、1、0 C.6、0、9 D.6、1
15. In the following expanded drawings, the left expanded view is ()
A B C D
16. Changing a curved road into a straight one can shorten the distance. The reason explained by geometric knowledge should be ()
A. There are two lines between the shortest; B. the length of the line can be determined
17. In order to estimate the number of fish in the lake, 50 fish are caught from the lake for marking, and then they are put back into the lake. After a period of time, when the marked fish are completely mixed with the fish group, when 200 fish are caught in the second time, 10 are marked, it is estimated that there are fish in the lake ()
A. 400 B. 600 C. 800 D. 1000
18. A workshop originally planned to produce a batch of parts in 13 hours, and then produced 10 more parts per hour. It took 12 hours not only to complete the task, but also to produce 60 more parts
A.13x=12（x+10）+60 B.12（x+10）=13x+60
C. D.
3、 Carefully solve a solution, you must be an expert in mathematics!
19. Demonstrate your computing power (4 points × 2 = 8 points)
（1） （2） ）
20. Demonstrate your ability to solve equations (4 points × 2 = 8 points)
（1）3（20-y）=6y-4（y-11） （2）
This is the angle of 3 plus the angle of 6
22. I believe you can do it! (8 points)
It is known that a and B are opposite to each other, C and D are reciprocal to each other, and y cannot be divisor,
Find the value of
23. As shown in the figure, ∠ cod = 116 °, BOD = 90 °, OA bisect ∠ BOC, and calculate the degree of ∠ AOD. (6 points)
4、 Think carefully, success must belong to you!
24. Be a clear consumer. (8 points)
Look at the picture below and read the dialogue carefully
Children: auntie, I'll buy a box of biscuits and a bag of milk
Salesperson: little friend, you used 10 yuan to buy a box of biscuits. But if you want to buy a bag of milk, you will lose 1 yuan. Today is children's day. I'll give you 20% discount on biscuits. Please take two kinds of things and give you 80 yuan change
According to the dialogue, how much is the price of biscuits and milk?
25. Exploration and discovery (2 points + 2 points + 2 points + 4 points = 10 points)
The continuous odd numbers 1,3,5,7,9 (1) what is the relationship between the sum of the five numbers in the cross box and the middle number 15?
(2) Let the middle number be a, and express the sum of five numbers in the cross box by algebraic expression
(3) Moving the cross box from top to bottom to left and right can frame the other five numbers. Is there such a rule for the sum of these five numbers?
(4) Can the sum of the five numbers in the cross box equal to 2005? If yes, please write down the five numbers; if not, explain the reasons
1 3 5 7 9
11 13 15 17 19
21 23 25 27 29
31 33 35 37 39
41 43 45 47 49
……
Sorry! I can't find the answer. You can do it yourself

15 questions on page 145 of mathematics volume 1 of junior high school First day mathematics page 145 question 15, want process and angle degree,,, thank you, feed that what day excrement, don't give me drag an adult appearance, this I have finished, do not need your help!

In fact, the conclusion can be drawn that the sum of the outer angles of a polygon is 360 degrees

11 question 1 100 * (- 3) * (- 5) * 0.01 (one ninth minus one sixth minus one eighteenth) * 36 (one fourth minus one half minus one eighth) * 128 [9 * (- 4)] * (negative quarter) 2.25 * (- 2.3) * three quarters (- 2.1) * 6.5 * (minus three seventh)

100×（-3）×（-5）×0.01 ＝100×3×5×0.01 ＝300×5×0.01 ＝1500×0.01 ＝15 ﹙1／9－1／6－1／18﹚×36＝36×﹙﹣1／9﹚＋36×﹙﹣1／6﹚＋36×﹙﹣1／18﹚＝﹙﹣4﹚＋﹙﹣6﹚＋﹙﹣2﹚＝﹣...

How to do math

subject
I can't find the math book

11 questions on page 61 in mathematics volume 1 of grade 1 of PEP

When n = 5, s = 12

11 questions on 3.2 extension and exploration of exercise 3.2 in mathematics volume 1 of junior high school published by people's Education Press It takes 20 seconds for a train to pass through a 300m long tunnel at a constant speed. There is a light on the top of the tunnel, which emits light vertically. The time for the light to shine on the train is 10s. Based on the above data, can you calculate the length of the train? In a hurry! Use two kinds of equations to solve (one set length, one set speed) It's not specific

If the train length is x meters, then the speed is (300 + x) / 20
Equation, 10 * (300 + x) / 20 = x, x = 300
If the train speed is x m / s, the train length is 10x
The equation 300 + 10x = 20x. X = 30. The same length is 300m

11 questions on the extension of exercises 3.1 in mathematics volume 1 of the people's Education Press

I am student
X-3 means to find out the first three digits of each letter
Standard answer

There are 20 exercises in mathematics volume 1 of junior high school

Self test of "rational number" ability in junior middle school algebra
(Full Score: 100 points, time: 90 minutes)
Fill in the blanks
(1) The opposite number of is______ The reciprocal of is______ The absolute value of is______ ;
(2) If, then=______ ;
(3) If_____ 0；
(4) Positive integers less than 3 have______ ;
(5) If______ ;
(6) If______ ;
(7) The rational number and its position on the number axis are shown in the figure,
Fill in the blanks with ">" or "<":
______ 0,______ Zero
2. Draw the dots representing the following numbers on the number axis, and then connect these numbers with ">" in order from large to small: (5 points)
3. Judge the right and wrong with "√" for right and "×" for wrong (4 points for each sub question, 20 points in total)
(1) The absolute value of a number must not be negative
(2) The opposite of a number must be negative
(3) The sum of two numbers must be greater than each addend
(4) If they are all positive numbers; ()
(5) If the absolute value of a nonzero number is equal to its opposite number, then the number must be negative
4. Multiple choice questions: (4 points for each sub question, 20 points in total)
(1) The following statement is correct ()
(A) The number with larger absolute value is larger;
(B) The number with larger absolute value is smaller;
(C) Two numbers with equal absolute values are equal;
(D) The absolute values of two equal numbers
(2) Of the following approximations obtained by rounding, the one with the accuracy of 0.001 and three significant digits is ()
（A）0.0207; （B）0.207;
（C）2.070; （C）20.700.
(3) If and are opposite to each other, then the following formula holds ()
（A） ； （B） ；
（C） ； （D）
(4) Zero is ()
(A) Natural number; (b) positive number;
(C) Non positive number; (d) rational number
(5) The number represented by the origin on the number axis and the point to the left of the origin is ()
(A) Negative number; (b) positive number;
(C) Non positive number; (d) non negative number
5. Calculation: (4 points for each of the first 4 questions and 6 points for the last two questions, 28 points in total)
（1） ；
（2） ；
（3） ；
（4） ；
（5） ；
（6）
6. Set value. (6 points)
Junior high school algebra Chapter 2 "rational number" ability self-test questions reference answers
1．（1） （2） （3） （4）1,2
（5） （6）0 （7）< （8）

Exercises in Chapter 2 of mathematics volume 1 of junior high school The type should be comprehensive (the "reading" above is the degree)

I suggest you buy "Tianfu mathematics", the above problem is more difficult