1. The following calculation is correct ()
a 、-24=-8 B 、(-2)3=-8
c 、-(-2)2= 4 D，
2. The parallelogram has no attribute of ().
A, diagonal lines are perpendicular to each other; b, opposite sides are parallel and equal.
C. Diagonal lines are equally divided. D. Diagonal lines are equal.
3. "Wear leather in the morning and gauze in the afternoon" is the best portrayal of the temperature in a day, which reflects ()
A, the average temperature b, the lowest temperature c, the highest temperature d, temperature range.
4. Simplify -{-(-a)-a-a}-a ()
a、0 B、-2a C、-4a D、2a
5. The following proposition belongs to the false proposition is ()
A triangle with two angles of 70 and 40 is an isosceles triangle.
A triangle whose bisector with an outer angle is parallel to one side is an isosceles triangle.
C in an isosceles triangle, the median lines of the two waists are equal.
D in an isosceles triangle with an angle of 36, there must be an angle of 72.
6. If it is known that the image of the inverse proportional function passes through point (a, b), then its image also passes through point ().
a 、(-a，-b) B 、( a，-b) C 、(-a，b) D 、( 0，0)
Fill in the blanks (this topic is entitled ***8 small questions, with 3 points for each small question and 24 points for * * *).
7. In order to make the score meaningful, X should meet the following conditions.
8. In △ABC, ∠ c = 90,
(1) If BC = 7 and AC=24, then AB =；;
(2) If BC = 5 and AB= 13, then AC =；;
(3) If AC = 15 and AB=25, then BC =.
9. Calculate with the square difference formula.
10.△ABC is converted into △ACD along AC, then ∠ ACB =, AB =.
1 1. If the ratio of two adjacent angles of a diamond is 1: 5 and the height is 1.5cm, then its circumference is.
12. For the following set of data: 7, 9, 6, 8, 10,1,the median is, and the average is.
13. As shown in figure 1, the bisectors of ∠ABC and ∠ACE intersect at point D, so the relationship between ∠ A and ∠D is shown in figure 2, and the bisectors of ∠ABC and ∠ACB intersect at point D, then ∠.
Figure 1 Figure 2
14. Translate the straight line y =-3x by 2 units along the Y axis, and then translate the straight line by 2 units to the left along the X axis.
Third, answer questions (***4 small questions, 8 points for each question, ***32 points)
15. Factorization 4a2b2-(A2+B2) 2;
16. Solve the fractional equation:
17. in △ABC, a∶b∶c=9∶ 15∶ 12. Try to determine whether △ ABC is a right triangle.
18. As shown in the figure, trapezoidal ABCD, AB ‖ DC, AD = DC = CB, the extension lines of AD and BC intersect with G. CE⊥AG at E, and CF⊥AB at F.
(1) Please write four groups of equal-length line segments in the diagram (except the known equal-length line segments);
(2) Choose a set of equal line segments you wrote in (1) and explain why they are equal.
Four, comprehensive questions (2 x10 = 20 points)
19. As shown in the figure, in △ABC, point O is the moving point on AB, and the straight line passing through point O MN ∠ BC, let the bisector CE of Mn ∠BCA be at point E, and the bisector CF of the outer corner of Mn ∠BCA be at point F.
(1) verification: OE = OF
⑵ When the point O moves to where, the quadrilateral AECF is a rectangle? And prove your conclusion.
20. It is known that the images of the inverse proportional function of the linear function y=mx+n and x all pass through the point (3, -4), and the distance from the intersection of the image of the linear function and the x axis to the origin is 5. Find the analytical expressions of (1) linear function and inverse proportional function; ⑵ Another intersection coordinate of two functions.
Answer: 1. B A D A B A
2.x≠3 and x ≠-1; 25, 12, 20 ; ( 12+ 1/3)( 12- 1/3)= 143 ; ∠ACD，AD； 12 ; 8.5,8.5; ∠A=2∠D，∠A = 180+2∠D； y=-3x+2，y =-3x-6；
3.( 1)-(a+b)(a-b)； ⑵x=0
(3) Let the short side be 9k, 12k and the long side be 15k, (k ≠ 0);
⑷GC=GD，GA=GB，CE=CF，DE = BF
Fourth, ①
②