Answer: 1. Multiple choice questions: (***30 points) BCCDD, CBBCD 2. Fill in the blanks: (***24 points)11.7,7-212.x ≤ 613.3 6544. 15.4016.40017.12318.x = 5, y = 3. Solution: (***46 points) 19. Solution: The first inequality can be transformed into X-.

X >-7。 The solution set of the original inequality group is -7.

X ≤ 1。 Representing the solution set on the number axis are:

20. solution: the original equation can be transformed into 89627170xxxxy ∴ 8960 828680xxxxy? When the two equations are subtracted, we can get 37y+74=0 and ∴ y =-2, so we get 32x. So the solution of the original equations is 322 xy? 21.∠ b = ∠ C. Reason: ∵ ad ∨ BC ∴1= ∠ b, ∠ ced = ∠ c ∠/. ∠ AEF = 55, so ∠ ACD =180-∠ ced-∠ d =180-55-42 = 83.23.a' (2,3). -7 1

-7-5548xy？ So there are 55 students in Class A and 48 students in Class B. Solution: If X section of A-type freight car is used, X section of B-type freight car is used, that is, 3525 (50)15301535 (50)165438. It is found that 28 ≤ x ≤ 30. Because x is an integer, x can only take 28, 29 and 30. Accordingly, the value of (5O-x) is 22,265,438+0,20. Therefore, * * * has three transportation schemes. Transport scheme 1: 28 sections for A-type trucks and 22 sections for B-type trucks; The second transportation scheme: 29 sections for type A trucks and 2 1 section for type B trucks; The third transportation scheme: 30 sections for A-type trucks and 20 sections for B-type trucks.

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