-
Mathematics examination questions in the middle of eighth grade
volume one
First, multiple choice questions
1. It is known that y 1=x-5 and y2=4x- 1, which makes the inequality y1>; Y2 is true, and the largest integer in the x value is ().
A.-2 B.-2 C.- 1 D.0
2. As shown in figure 1, given OA=OB, OC=OD, and AD and BC intersect at E, the number of congruent triangles in the figure is ().
A.2 B.3 C.4 D.5
( 1) (2) (3)
3. As shown in Figure 2, a classmate broke a triangular piece of glass into three pieces, and now he wants to go to the glass shop to match an identical piece of glass, so the most convenient way is ().
A. from ① to B. From ② to C. From ③ to d. From ① to ②.
4. given points (-2, y 1), (-1, y2) and (1, y3) are all on the straight line y=-x+b, then the relationship between the values of y 1, y2 and y3 is ().
a . y 1 & gt； y2 & gty3 b . y 1 & lt； y2 & lty3 C.y3 & gty 1 & gt； y2 D.y3 & gty 1 & gt； y2
5. The image of function y=kx+b is parallel to the image of function y=-x+3, and the intersection with the Y axis is m (0 0,2), so its function expression is ().
A.y=x+3 B.y=x+2 C.y=-x+3 D.y=-x+2
6. As shown in Figure 3, △ ABC △ bad, A and B, C and D are the corresponding vertices. If AB=6cm, BD=5cm and AD=4cm, then the length of BC is ().
A.4 cm, B.5 cm, C.6 cm, D.
7. It is known that the ordinate of the intersection of the image of the linear function y 1=(m2-2)x+ 1-m and y2=(m2-4)x+2m+3 and the Y axis is reciprocal, so the value of m is ().
A.-2b 2c-3d-4
8. If the straight line y=2x+3 and y=3x-2b intersect the X axis, the value of b is ().
A.b=-3 B.b=- C.b=- D.b=6
Second, fill in the blanks
1. It is known that y-2 is directly proportional to X. When x=3, y= 1, then the functional relationship between Y and X is _ _ _ _ _.
2. In the sector statistical chart, if the central angle of a sector corresponding to a certain part is 36, then the percentage of that part in the total is _ _ _ _ _.
3. It is known that △AB'C' △ a ′ b ′ c ′, A and A ′, B and B' ′ are corresponding vertices, and the circumference of △ ABC is 12cm, AB = 3 cm, BC=4cm, then A ′ b ′ = _ _ _ cm, B ′ c ′.
4. As shown in Figure 4, ∠ b = ∠ d = 90. To prove that △ ABC and △ ADC are equal, the supplementary condition is _ _ _ _ _ _.