First, multiple choice questions
1, in the algebraic expression, the fraction is ()
a，2 B，3 C，4 D，5。
2. If the inverse proportional function image passes through the point p (2,3), the () on the function image is one of the following points.
3. The average diameter of adult mature red blood cells is generally 0.000007245m, which can be expressed as () by scientific notation.
A, B, C, D,
4. It is known that in diamond ABCD, diagonal lines AC and BD intersect at point O,
OE∨DC intersects BC at point E, and AD = 6 cm, then the length of OE is ().
A, 6cm b, 4cm c, 3cm d, 2cm
5. Given the sample data of 5, 6, 7, 8 and 9, the variance is ().
a、 10 B、C、2 D、
6. Fold a piece of paper into a parallelogram once, so that the crease bisects the area of the parallelogram. So this origami method * * * has ()
A, 1 species b, 2 species c, 4 species d, countless species.
7, in the following statement, the correct number is ()
① Given that the area of a right triangle is 2 and the ratio of two right angles is 1: 2, the length of the hypotenuse is;
② The maximum side length of a right triangle is, the shortest side length is 1 and the other side length is;
(3) In, if, a right triangle;
④ The area of an isosceles triangle is 12, the height on the base is 4, and the waist length is 5.
a， 1 b，2 c，3 d，4
8. In the same coordinate system, the approximate positions of the images of the linear function y = kx-k and the inverse proportional function may be () in the figure below.
A B C D
9. As shown in the figure, it is known that the moving point p moves on the image of the function.
PM⊥x axis at point M, PN⊥y axis at point N, line segments PM and PN.
If they intersect the straight line AB: Y =-X+ 1 at points E and F, then AF is.
The value of is ()
A, B, C, D,
10. in △ABC, AB= 15, AC=20, and ad beside BC =12.
The length of BC is ()
A, 25 B, 7 C, 25 or 7 D, uncertain
1 1 As shown in the figure, if EF passes through the intersection o of the diagonal of rectangular ABCD and intersects AB and CD at E and F respectively, the area of the shaded part is () of the area of rectangular ABCD.
A, B, C, D,
12 As shown in the figure, in □ABCD, e and f are the midpoint of the sides of AD and BC respectively, and AC intersects with BE and d F at G and H respectively. Try to judge the following conclusions:
①δABE?δCDF； ②AG = GH = HC； ③EG=
④S△ABE=S△AGE, in which the correct conclusion is ()
a . l . b . 2c . 3d . 4
Second, fill in the blanks
13, when x=2, the score is meaningless, so when x=3, the value of the score is.
14. If the fractional equation about x has no solution, the value of the constant m is.
In 15 and trapezoidal ABCD, ABCD, E, F, G and H are the midpoint of AB, BC, CD and DA, respectively. When the sides of the trapezoid ABCD meet the conditions, the quadrilateral EFGH is a diamond.
16, the total score of a student's seven subjects is 560, of which three subjects have a total score of 234, and the other four subjects have an average score of _ _ _ _ _ _ _.
17, the inverse proposition of the proposition "rhombus is a quadrilateral with diagonal lines perpendicular to each other" is.
18, known and mutually opposite numbers, then the triangle with X, Y and Z as sides is
Triangle. (Fill in "right angle", "isosceles" and "arbitrary")
19 As shown in the figure, point A is any point on the inverse proportional function. If point A is AB⊥x axis is at point B, then S△AOB=.
20. As shown in the figure, at Rt△ABC, AC=5, BC= 12, three semicircles are made upward with its three sides as the diameter, and the shadow area is.
III. Answering and Proving Questions
2 1, calculate (1) (2) (-2m2n-2) 2 (3m-1n 3)-3.
22, solve the equation:
23. The balloon is filled with a certain amount of gas. When the temperature is constant, the air pressure in the balloon is inversely proportional to the gas volume. Its image is shown in the figure. When the air pressure in the balloon is greater than 100, the balloon will explode. For safety reasons, please find out the range of gas volume.
24. On February 28th, 2004, the first intercity railway in China-Hening Railway (Hening) officially started construction. After completion, the running mileage of Hefei-Nanjing railway will be shortened from the current 3 12km to 154km, and the design speed is 2.5 times of the current speed. Therefore, the running time of passenger trains will be shortened by about 30 13h, and the design speed of Hening Railway will be sought.
25. The picture below shows the age structure histogram of a basketball team. According to the information in the picture, answer the following questions:
(1) Average age of team members;
(2) Model and median age of team members.
26. As shown in the figure, when the rectangle ABCD is folded in half along BD so that the point C falls at the position where C', BC' and AD intersect at E, if AB=6cm and BC=8cm,
Find the area of the overlap △ bed.