1. Among the four figures in the figure below, the one that is not at the same angle is ().
A.① B.② C. ③ D.④
2. The following equations: ①; ② ; ③ ; (4) There are () A. 1 B.2 C.3 D.4 These are binary linear equations.
3. In the following groups, the solution of the binary linear equation 3x-y=5 is ().
A.B. C. D。
4, the following operation is correct ().
A.a2+a3=a5 B. a2a4=a8C。 (a2)3=a5 D.a6a2=a4
5. The following calculation is incorrect ().
A.(-2)-2 =- 14 b .( 13)-2 = 9 c . 20050 = 20080d . 3.2 10-4 = 0.00032。
6. Simplification: (-m) 12(-m)3 equals ()
a . M4 B- M4 c . M9 d-M9
7, as shown in the figure on the right, point on the extension line, you can judge () in the following cases.
A.B.
C.D.
8, a student practice driving a car, after two turns, and the original direction, the angle of the two turns may be ().
A. Turn left for the first time and right for the second time.
C. Turn right for the first time and turn right for the second time. D. Turn left for the first time and turn left for the second time.
9、
(A)- 1.5(B)(C)- 1.5(D)- 1
10. Fold a corner of the square ABCD. The crease is AE (as shown in figure 1), and the defect is 48. 5% bigger than BAE.
Let the degrees of BAE and BAD be x and y, respectively, then the appropriate equations are ().
A.B. C. D。
Second, fill in carefully (there are 8 small questions in this question, with 3 points for each small question and 24 points for * * *).
1 1、 = _________。
12, expressed in decimal:10-3 = _ _ _ _ _ _; 1.54 10-5=________。
13 and -0.0005008 are expressed in scientific notation as _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
14, if, y is represented by an algebraic expression containing X.
15, as shown in the figure, if l 1∑L2, 1=45, then 2 = _ _ _ _.
16. As shown in the figure, B, A and E are on the same straight line. Please add a condition to make AD∨BC. The condition you added is _ _ _ _ _ _ _ (auxiliary lines are not allowed).
17, if, then =
18, if! Is a mathematical operation symbol, and 1! = 1,2! =2 1=2,3! =32 1=6,4! =432 1 is 100! 98! The value of 99 is _ _ _ _ _.
Third, do the questions and pay attention to careful examination! (7 small questions in this question, ***46 points)
19, calculation: (8 points for this question) (1)5 (2)
20. (4 points in this question) Solve the following binary linear equation:.
2 1, (6 points in this question) simplify first, and then evaluate. (x+2y) (x-2y)+(9x3y-12xy3+3xy2) (-3xy), where x= 1 and y=-2.
22. (Subject 6 points) Translate the line segment AB in the grid paper as shown in the figure, and draw the following graphics after translation respectively:
(1) translate 5 units up and 2 units to the right to get the line segment A1b1;
(2) Translate 4 units to the right, and then translate 3 units upwards to obtain a line segment A2b2;
(3) For the line segments A 1 B 1 and A2 B 2 obtained in (1)(2) above, please describe how A 1 B 1 is translated to get A2B 2 (just write a translation).
23. (6 points in this question) As shown in the figure, CD∑AB, DCB=70, CBF=20, EFB= 130, what is the positional relationship between straight line EF and AB, and why?
24. (7 points in this question) We cut a rectangle with a length of 2a and a width of 2b shown in the left picture above into four small rectangles along the dotted line, and then form a larger square, as shown in the right picture above.
(1) The side length of a big square is _ _ _ _ _ _ _ _;
(2) The side length of the middle square (shaded part) is _ _ _ _ _ _ _ _;
(3) The area of the shadow part can be expressed as _ _ _ _ _ _ _ _ _ _ _; It can also be expressed as _ _ _ _ _ _ _.
(4) Comparing the above two methods, we can get the equivalence relation as _ _ _ _ _ _ _ _ _ _;
(5) Can the following problems be solved with the help of the obtained equivalence relation? Give it a try!
Given a-b= and ab=2, find the value of (a+b)2.
25.(9 points) A middle school has newly built a 7-storey teaching building with 8 classrooms on each floor. There are 8 doors in and out of the building, of which 4 main doors are the same size and 4 side doors are the same size. Eight doors were tested during the security check: when a main entrance and two side doors were opened at the same time, 560 students could pass in 2 minutes; When a main entrance and a side door are opened at the same time, 800 students can pass in 4 minutes.
(1) How many students can pass through a main entrance and a side door every minute on average?
(2) During the inspection, it was found that the efficiency of going out would be reduced by 30% due to the crowded students in an emergency. According to the safety inspection regulations, in case of emergency, students in the whole building should be evacuated safely through these eight doors within five minutes. Suppose there are at most 45 students in each classroom of this teaching building. Q: Do the eight doors meet the safety regulations? Please explain the reason.