Hunan education printing plate eighth grade first volume mathematics final examination paper
Choose one first and read the four options before making a decision! * * * 3 points for each small question, ***30 points * * *
1. Of the following four patterns, * * * * cannot be obtained by rotating the basic pattern.
2. The arithmetic square root of * * * x2+1* * * 2 is * * * *.
a . x2+ 1 b . * * * x2+ 1 * * * 2 c . * * * x2+ 1 * * * 4d . * * * x2+ 1 * * *
3. If, then ***xy***3 is equal to * * * *
A.3 B.-3 C. 1 D.- 1
4. If A and 3 are antonyms, then the reciprocal of |a-3| is equal to * * * *.
A.B. C. D。
5. Given that A***2, -5*** and AB are parallel to the Y axis, the coordinate of point B may be * * * * *.
A.* * *-2.5 * * * b . * * * 2.6 * * * c . * * * 5，-5 * * * d . * * *-5.5 * * *
6.y = * * m+3 * * * x+2 is a linear function, and y decreases with the increase of independent variable x, so the value of m is * * * * *.
In the morning & lt3 B.m & lt-3 C.m=3 D.m≤-3.
7. The image * * of the known linear function y=kx+b is shown in figure 1***, when x
A.y> B.y & gt-2 BC
C.-2
8. Known straight line y = kx-4 * * * k
a . y =-x-4 b . y =-2x-4 c . y =-3x+4d . y =-3x-4
9. As shown in Figure 2, OD=OC, BD=AC, ∠O=70 degrees, ∠C=30 degrees, then ∠BED is equal to * * * *.
45 degrees 50 degrees 55 degrees 60 degrees
10. As shown in Figure 3, AB=DC, AE=DF, BF=CE. The following questions are not necessarily true * * * *.
A.∠B =∠C B . AF∨DE
C.DC
Second, fill in and believe in your own ability! * * * 3 points for each small question, ***30 points * * *
1. Simplified:.
2. If:, then x=, y=.
3. If,, then.
4. The point ***3, -2*** firstly translates 2 units to the right, and then translates 4 units upwards, and the coordinates of the obtained point about the Y axis are.
5. It is known that A * * x+5, 2x+2 * * is on the X axis, so the coordinates of point A are.
6. Given that the coordinates of the intersection of the image of a linear function with the X axis and the Y axis are ***-2, 0***, * * 0, 4***, the analytical expression of the function is.
7. Write the analytical formula of a linear function with the following conditions: * *1* * y decreases with the increase of x:. ***2*** The image passes through the point *** 1, -3***:.
8. As shown in Figure 4, in △ABC, d is the midpoint of AC. If BD continues until E and DE are equal, then △ DAE △ DCB.
9. As shown in Figure 5, MB=ND, ∠MBA=∠NDC and the following four conditions are known: ①AM=AB, ②AC=BD, ③BM=AB, ④AM=CN, in which △ ABM △ CDN can be determined.
10. As shown in Figure 6, it is known that △ABC and △BDE are equilateral triangles connecting AD and CE. If ∠ bad = 39, then ∠BCE=.
Third, when doing it, pay attention to careful inspection! * * * This big problem ***50 points * * *
1.* * 10 Point * * * Find the value of x in the following categories:
①* * * x-2 * * * 2 = 25②-8 * * * 1-x * * * 3 = 27
2.*** 10 * * As shown in Figure 7, it is known that AB∨CD, AD∨BC, F are on the extension line of DC, AM=CF, FM is on the extension line of DA, and BC is on E.N. Try to explain: AE=CN.
3.*** 10 point * * As shown in Figure 8, it is known that at △ABC, ∠ ACB = 90, D is a point on the side of AC, E is the midpoint of DB, the extension line of CE intersects AB at F point, and FG∨BC intersects DB at G point. Try to explain: ∠ BFG.
4.*** 10 min * * * A factory has two production lines, A and B, which have been put into production successively. The relationship between the output of two production lines * * * tons * * and time * * * days * * is shown in the figure. Answer the following questions according to Figure 9:
(1) How many tons of finished products has production line A produced before production line B was put into production?
(2) How many tons of finished products are produced by production lines A and B respectively every day?
③ Find the analytical expression of the function corresponding to two straight lines in the graph.
5. * *10 score * * * A school plans to organize some teachers to travel to Zhangjiajie in the summer vacation, and the estimated number is between 7- 13. The service quality of travel agencies A and B is the same, and the external quotations are all from 300 yuan. When the company contacted, a travel agency said that it could give each tourist a 20% discount; B travel agency said,
One tourist can be exempted from the travel expenses first, and the remaining tourists can enjoy a 10% discount.
① Write the functional relationship between the travel expenses Y and the number of people X reported by two travel agencies respectively.
② If there are 1 1 people traveling, which travel agency should I choose?
③ Within what scope, you should choose a travel agency; Within what scope should I choose B Travel Agency?
Fourth, explore and innovate and make persistent efforts! * * * This big problem 10 score * * *
A communication company has set up two kinds of communication services: users pay 50 yuan monthly fee first, and then pay 0.4 yuan phone bill every 1 minute; "Autoexpress": No monthly fee, and 0.6 yuan is paid for every 1 minute call. If the call time is x minutes in one month, the costs of the two methods are 65,438+0 yuan and y2 respectively.
* * *1* * Write the functional relationship between y 1, y2 and x. 。
***2*** How many minutes is the call a month, and the charges for two mobile communications are the same?
***3*** It is estimated that someone will talk for 300 minutes a month. What kind of mobile communication should he choose?
Hunan education printing plate eighth grade first volume mathematics final examination paper answer.
I. 1. D 2。 A 3。 D 4。 C 5。 B
6.B 7。 D 8。 B 9。 B 10。 C
Second, 1. 2., 3.4.5.
6.7. Wait, wait. 8.9.② 10.
3. 1.①, ② 2. Therefore.
3. Therefore.
4.① tons; ② A ton, b ton; ③ , .5.① , .
② Travel agency A should be selected.
(3) When the number of people is 100, it is the same to choose two tours. When the number of people is less than 100, travel agency B should be selected; When there are many people, you should choose a travel agency.
4. * * *1* * * * * is an integer greater than or equal to * * * *.
* * * is an integer greater than or equal to * * *;
***2*** minutes;
***3*** "GSM".