1, if 2x-3y=5, then 6-4x+6y = _ _ _ _ _.
2. It is known that the sum of number A and number B is 13, and number B is 5 less than number A, then number A is _ _ _ _ _ _ _ _ _ _ _ _ _.
3. If (y-3x+1) 2+| 2x+5y-12 | = 0, then x=____, and y = _ _ _ _.
4. If the equation and the equation y=kx- 1 have a common * * solution, then k = _ _ _ _ _ _
5.( 10 Jiangxi) A class of 40 students went to the show and bought two kinds of tickets * * * to go to 370 yuan, including one first-class ticket 10 yuan and one second-class ticket in 8 yuan. Suppose you buy X tickets in first class and Y tickets in second class, from which you can list the equations. .
6. If: known, then ab =.
7. If the solution of the equation is, then.
8. Given that the sum is the solution of the equation ax+by=0(b≠0), then c = _ _ _ _ _ _ _
9. If the solution of the equations is that a student misreads C and finds that the solution is yes, the correct value of C is _ _ _ _ _ _ _ _, and b = _ _ _ _ _ _ _
Second, multiple-choice questions: (4 points for each question ***28 points)
1, in the following equations, belongs to the binary linear equations is ().
A, B, C, D,
2. In the equation, if it is a solution, then the values of a and b are ().
A.a= 1, b = 2 b It cannot be uniquely determined.
C.a=4，b=0 D.a=，b=- 1
3. Athletes in a school are trained in groups, if there are 7 people in each group, the rest are 3 people; If there are 8 people in each group, there are 5 people missing; Setting action
If the number of members is x and the number of groups is y, the system of equations is ().
A, B, C, D,
4, the solution of the equation is ()
A, a group of solutions B, two groups of solutions C, no solution D, and countless groups of solutions
5. If the solution of binary linear equations satisfies the equation x-2y=5, then the value of k is ().
A. BC-5 years BC 1
6. The solution of the equations 12 x+ 13 y=3ax-y=a is ().
a、x=4ay=3a B、x=-4ay=-5a C、x = 165 ay = 1 15a D、x= 16ay= 17a
7. If the binary linear equation 5x-2y=4 has a positive integer solution, then the value of x is ().
A, even b, odd c, even or odd d, 0
8. The distance between A and B is 360 kilometers. When a ship travels between A and B, it takes 18 hours downstream and 24 hours upstream. If the speed of the ship in still water is X km/h and the current speed is Y km/h, the correct term in the following equation is ().
A.B.
C.D.
Three, solve the equation (5 points per question, ***20 points)
1、 2、
Iv. Answer questions (6 points for each question, *** 14 points)
1. When solving the equations bx+ay= 10x-cy= 14, A correctly solves x=4y=-2, and B misspells c to get x=2y=4. If there is no mistake in their operation, find the values of A, B and C. ..
2. Someone bought two kinds of stocks, A and B, with 24,000 yuan, and sold them when A stock appreciated 15% and B stock fell 10%, making a profit 1350 yuan. How much did someone buy?
(2011Hengyang, Hunan) Last year, Uncle Li contracted 10 mu to plant vegetables A and B, and made a profit of18,000 yuan, including 2,000 yuan for vegetables and B 1500 yuan.
4. (Chongwen District, Beijing, 20 10) A train from Beijing to Guangzhou takes about 15 hours. After the train leaves, it will travel at a constant speed for 8 hours and then arrive in Wuhan. Since the Wuhan-Guangzhou high-speed railway, the world speed railway, was officially put into operation in June 2009, the average speed of trains from Wuhan to Guangzhou is now 50 kilometers more than twice that of the original, and the time required is also shorter than the original.
5.(20 10 Fujian Dehua) A store needs to purchase 160 pieces of A and B. The purchase price and selling price are as follows: (Note: profit = selling price-purchase price)
(1) If the store plans to make a profit of 1 100 yuan after selling the goods, how many pieces should Party A and Party B buy respectively?
(2) If the store plans to invest less than 4,300 yuan and the profit after selling this batch of goods is greater than 1260 yuan, what kinds of purchase schemes are there? And write a profitable purchase plan directly.
Jiayi
Purchase price (RMB/piece) 15 35
Price (RMB/unit) 20 45
Fill in the blanks
1.–4 2.9, 4 3.x= 1，y = 2 ^ 4。
5.6.-75 7.3, 1 8.6 9. 1, -2
Second, multiple choice questions
1.D 2。 C 3。 C 4 explosive C 5。 B 6。 A seven. An eight. A
Third, solve the equation
1.2.3.4.
Fourth, answer questions.
1.a= 1，b=3，c=5
2.a shares are 15000 and B shares are 9000.
Suppose uncle Li planted mu of vegetables A and mu of vegetables B last year. So, suppose Uncle Li planted mu of vegetables A and B last year.
The average speed of trains from Beijing to Wuhan is kilometers per hour, and the average speed of trains from Wuhan to Guangzhou after speeding up is kilometers per hour.
Solve the equation and get
A: The average train speed from Beijing to Wuhan is 150 km/h, and the average train speed from Wuhan to Guangzhou is 350 km/h after speed increase.
5.( 1) Suppose that commodity A needs X pieces and commodity B needs Y pieces.
According to the meaning of the question, you must
solve
Answer: A purchases 100 pieces, and B purchases 60 pieces.
(2) Suppose commodity A buys commodity A, then commodity B buys commodity A (160-a).
According to the meaning of the question, you must
Solve the inequality group and get 65.
∫a is a non-negative integer, and ∴a takes 66,67.
∴ 160-a take 94 and 93 respectively.
A: There are two cargo construction schemes. Scheme 1: Buy 66 A-class goods and 94 B-class goods; Scheme 2: Buy 67 items of Class A and 93 items of Class B, of which Scheme 1 is profitable.