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Mid-term math problems in the second volume of the first day of junior high school
1. Fill in the blanks: (2 points for each question, ***30 points)

1. If ∠ A = 23 34', ∠ B = 7145', ∠ A+∠A+∠B = _ _ _ _'.

2._ _ _ _ _ _ is the shortest line segment connected by points outside the line and points on the line.

3. As shown in figure 1, in a cuboid, the plane is perpendicular to the edge AD.

There are _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

4. As shown in Figure 2, when ∞ _ _ = ∞ _ _ _,

200 BC

5. As shown in Figure 3, AB‖CD, ∠2 is greater than ∠ 1.

2 times larger than 6, then ∠ 2 = _ _ _ _.

6. The proposition of "equal vertex angles" is: _ _ _ _ _ _ _ _ _ _ _,

The conclusion is _ _ _ _ _ _ _ _ _ _.

7. When x _ _ _ _ _ _ _ _ _ the algebraic expression 1-3x is nonnegative.

8.

9. Expressed in scientific notation: 0.000602 = _ _ _ _ _ _.

10.

1 1.

12. When _ _ _ _ _, (2a+ 1)0= 1.

13. calculation: (a+2) (a-2) (a2-4) = _ _ _ _ _ _ _.

14. As shown in Figure 4, D is the midpoint of AC, and AD=3.

15. If

2. Multiple choice questions: (2 points for each question, ***20 points)

16. Among the following propositions, the correct one is ().

(a) Of all the straight lines connecting two points, the straight line is the shortest.

(b) Two straight lines are cut by a third straight line and equal to the complementary angle.

(c) Two disjoint straight lines are called parallel lines.

(d) If both straight lines are perpendicular to the third straight line, the two straight lines are parallel to each other.

17. as shown in figure 5, if AB ‖ DE, ∠ B = 120, ∠ D = 25, ∠C= ().

50 (B) 80 (C) 85 (D) 95

18. When two parallel lines are cut by a third straight line, a set of bisectors at the inner corner of the same side are mutually ().

(a) vertical (b) parallel (c) coincident (d) intersecting, but not vertical.

19. As shown in Figure 6, if ∠ 1=∠2, the wrong conclusion is ().

(A)3+∠4 = 180(B)5 =∠4

(C)5 =∠7(D)6+∠7 = 180

20. given AB ‖ CD and CD ‖ ef, AB‖EF. The basis of this reasoning is ().

(a) Parallel axiom (b) Equivalent substitution (c) Internal dislocation angles are equal and two straight lines are parallel.

(d) Two lines parallel to the same line are parallel.

2 1. If ∠A and ∠B are parallel, and ∠A is 30 smaller than ∠B, then ∠B is ().

(a) 30 (b) 70 (c) 30 or 70 (d) 100.

22. In the following equation, the error is ().

(A)(A-B)2 =(B-A)2(B)(A+2b)2 = a2+4b 2

(-A-b)2 =(A+b)2(D)(A+b)2-(A-b)2 = 4ab

23. As shown in Figure 7, it is an L-shaped steel bar with a cross-sectional area of ().

(a) CT+ST (b) CT+ST-T2 (c) CT+ST-2t2 (d) are all wrong.

24. In the following operations, the correct one is ().

(A)(3a6b)2 = 6a 12 B2(B)(8a2b-6ab 2)÷2ab = 4a-3b

(C) (D)(X-2Y)(2y-x)=x2-4xy+4y2

25.if- 1 < x & lt; 0, the value of the algebraic expression x( 1+x)( 1-x).

(a) It must be positive; (b) It must be negative; (c) It must be non-negative; (d) The pros and cons are uncertain.

Three. Solution: (5 points for each question, ***35 points)

26. Calculation: (3m-2n)(2n+3m) 27. Calculation: (a-3)(a2+3a+9)

28. It is known that | 2x+y-1|+(5x-4y-8) 2 = 0. Find the value of xy.

29. Calculation: (3x2-2x+1) (3x2+2x-1)

30. Calculation: (-2xay) 2 (xa-2ya) 4 ÷ [(-xy2) 2] a

3 1. Calculation: (m-3n)2-(3n+m)2

32. If x+y = 2, xy = k+4 and (x-y) 2 = 12, find the value of k. 。

First, multiple-choice questions (2 points for each small question, 20 points for * * *)

The solution of 1. equation is ()

(A) x=0 (B) x= 1 (C)x=2 (D)x=3

2. The equation whose solution is x=4 is ()

(A)7x = 3x-4(B)2x+ 1 = 3-x(C)2(3-x)=-2(D)

3. When x = 1, the solution of equation 3x-m+ 1=0, then the value of m is ().

(A) - 1 (B) 4 (C) 2 (D) -2

4. If the algebraic expression 4x-7 is equal to the algebraic expression 5(x+), then the value of x is ().

(A) -9 (B) 1 (C) -5 (D) 3

5. If 2x-7y=8, then it is correct to represent x () with the algebraic expression of y..

(A) (B) (C) (D)

6. The equation solved is ()

(A) (B) (C) (D)

7. If the monomials xm+2ny and x4y4m-2n are similar terms, then the values of m and n are ().

(A) m=- 1,n= (B) m= 1,n= (C) m=2,n= 1 (D) m=-2,n=- 1

8. When solving the equation by addition and subtraction, (1)2-(2) gets ().

(A)3x =- 1(B)-2x = 13(C) 17x =- 1(D)3x = 17

9. After a down jacket is reduced by 10%, the price is 270 yuan, and 60% of the original price is its cost, so its cost is ().

(1) 300 yuan (2) 290 yuan (3) 280 yuan (4) 180 yuan.

10. If an outer angle of a triangle is smaller than its adjacent inner angle, then the triangle is ().

(a) acute triangle (b) right triangle (c) obtuse triangle (d) cannot be determined.

Fill in the blanks (2 points for each small question, 20 points for * * *)

1 1. The solution of the equation 1.8x-4.8=0 is.

12. If 3m-5=4, then m2+m=.

13. This equation is named.

14. The solution of the equation is.

15. A number plus 5 equals its 2 times minus 9. Let a number be x and get the equation.

16. Given that two sides of a triangle are 2cm and 7cm respectively, the value of the third side is odd, and the circumference of this triangle is.

17. I bought five exercise books and spent 23.9 yuan on two pens. If a pen is 3.2 yuan, then every exercise book is RMB.

18. If |x-2|+(x-y+3)2=0, then (x+y)2=.

19.a and B are one kilometer apart. A Walk 5 kilometers per hour and 7 kilometers per hour. They set out from A and B at the same time, face to face, and met a few hours later.

20. There are some apple boxes. If each box contains 25 kilograms of apples, there is nowhere to put the remaining 40 kilograms of apples. If each box contains 30 kilograms, there are 20 empty boxes. There is only one of these apple boxes.

Third, solve the equation (or equations) (2 1~23 small questions each small question 4 points, 24~26 small questions each small question 6 points, ***30 points)

2 1.3x-2=5x+6

22.

23.

24.

25.

26.

Iv. Answer questions (5 points for each question, *** 10)

27. Solving the equation is generally to simplify the original equation into

Then use substitution method or addition and subtraction method to solve. Besides, is there an easier way? If yes, please explain.

28. As shown in the figure, in △ABC, AD is the angular bisector, ∠B=660, ∠C=540. Find the degree of ∠ADB and ∠ADC

Five, column equation or equation solving application problems (7 points for each small question, *** 14 points)

Xiao Qiang learned 60 pages by himself in three days, and the next day he learned 4 pages more than the first day. On the third day, I taught twice as many pages as on the first day. How many pages did he learn for Xiao Qiang in three days?

30. Two batches of goods shipped to the disaster area, the first batch of 480 tons, just loaded with 8 train cars and 20 cars; The second batch of goods ***524 tons, just loaded with 10 train cars, 6 cars. How many tons are loaded in each train car and each car on average?