1. In the equation, it is represented by the algebraic expression contained.
2. The market demand D (1000 pieces) and the unit price P (yuan/piece) of a commodity obey the demand relationship: when the unit price is 4 yuan, the market demand is (1000 pieces).
3. The solution of binary linear equations is.
4. In quadrilateral ABCD, if ∠A, ∠B, ∠C and ∠D, each angle is 30 smaller than the last one, and ∠D is the largest, then ∠B has a degree of.
5. As shown in the figure, in △ABC, AB= 10cm, the middle vertical line ED of AC intersects with AC at E and with AB at D. If BC=6cm, the circumference of △CDB is cm.
6, called the solution of the equation, then.
7. Grandpa plays chess with his grandson. Grandpa won 1 set, recorded 1 point. Sun Zisheng 1 set, score 3 points. After eight sets, the two scored the same, so grandpa won.
8. If the size of one angle of an isosceles triangle is equal to 30, the size of the vertex angle of this isosceles triangle is.
9. A company has nine employees and a manager. The monthly salary of the manager is 20,000 yuan, and the salaries of nine employees are as follows (unit: yuan): 2000,2050,2100,2100,2150,200,2250,220.
10, as shown in the figure, D is the midpoint of AC on the edge of equilateral △ABC, E is a point on the extension line of BC, CE BC, then △DBE is a triangle.
Second, multiple choice questions
1 1, the following groups of length line segments are edges, and the one that can form a triangle is ().
a、7cm、5cm、 12cm B、4cm、5cm、6cm C、6cm、8cm、 15cm D、8cm、4cm、3cm
12, the number of school basketball is 2 times less than that of football, and the ratio of basketball to football is 3∶2. Find the number of two kinds of balls. If there is a basketball and a football, the equations obtained according to the meaning of the question are ()
A, B, C, D,
13. If the sum of the inner angles of a polygon is equal to the sum of the outer angles, then the polygon is ().
A, quadrilateral b, pentagon c, hexagon d, heptagon.
14. Among the following events, the confirmed event is ().
A, roll the dice at 6 o'clock. B, buy a movie ticket, the seat number is even.
C, it will snow in winter in Heilongjiang D, from the pocket containing three red balls and two white balls, I find out that one ball is a red ball.
15, given the following combination of regular polygons with the same side length, the one that cannot be paved is ().
A, regular triangle and square combination b, regular triangle and square combination.
C, combination of square and regular hexagon D, combination of regular triangle, square and regular hexagon
16, as shown in the figure, in △ABC, AB=AC, D is any point on the side of BC, DF⊥AC is on the side of F, E is on the side of AB, ED⊥BC is on D, ∠ AED = 155, then ∠EDF and so on. ().
a、50 B、65 C、70 D、75
17, a shopping mall sells 1 1 pairs of Li Ning brand sports shoes a day, and the sales of shoes of various sizes are shown in the following table, so in a set of data composed of the sizes of 1 1 pairs of shoes, the mode and median are () respectively.
Size of shoes (unit: cm)
23.5
24
24.5
25
26
Sales volume (unit: double)
1
2
2
five
1
a、24、25 B、26、25 C、25、24.5 D、25、25
18, the following figure, is not necessarily an axisymmetric figure ().
A, line segment b, angle c, right triangle d, isosceles triangle
19. There is a fish pond by the road. The sign standing next to it says that the average water depth of this pond is 1.50 meters, and Xiaoming is 1.70 meters tall. He can't swim. The result of Xiaoming jumping into the fish pond is ().
A, it won't drown B, it will drown C, and it may or may not drown D. None of the above answers are correct.
20. A customer went to the store to buy shoes, only knowing that his old size was 43, but he didn't know what new shoe size to wear. He remembered that the old size was calculated by adding a number, and the new shoe size was the new shoe size. Because the old and new sizes of his son's shoes are integers and easy to remember, he knows that his old size is 40 and his new size is 25. Now please help the customer calculate the size of his new shoes ().
26.5 degrees Celsius, 26 days, 25.5 degrees Celsius
Third, answer questions.
2 1, solving equation: 22, solving equation:
23. If one side of the isosceles triangle is 8cm long and its circumference is 18 cm, find the waist length of the isosceles triangle.
Fourth, answer the question (this big question has four small questions, each with 4 points, *** 16 points)
25, solve the equation:
26. It is known that the circumference of △ABC is 18cm, and the length of three sides is.
27. As shown in the figure, DE is the median vertical line of waist AB of isosceles △ABC, which intersects AB in D and AC in E,
If < c = 70, find the size of < ∠AEB.
Verb (abbreviation of verb) solving problems (2 small questions in this big question, 6 points for each small question, *** 12 points)
29. Some cards are marked with 6, 12, 18, 24, …. Xiao Ming took three cards. Their numbers are adjacent, and the sum of the numbers is 342.
(1) What three cards did Xiao Ming get?
(2) Can you get three cards with adjacent numbers so that the sum of their numbers is 86? Why?