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It takes about 15 hours for a train to start from Beijing to Guangzhou. After the train starts, it runs at the original speed for 8 hours and then reaches Wuhan. Due to world time
Let the average speed from Beijing to Wuhan be X
15X=8X+（15-8-4）（2X+50）
The solution is x = 150
2 times 150 + 50 = 350 (km / h)
A: the average speed from Beijing to Wuhan is 150 kilometers per hour
After the acceleration, the average speed from Wuhan to Guangzhou is 350 kilometers per hour
How long is the trunk of a train? How many are there in a train
1. Passenger cars are generally 15-20;
2. Freight cars are 1-60 ordinary freight cars, and heavy-duty freight cars (special for coal transportation on Daqin Railway) can reach more than 100
3. 4-20 commuter cars (departure and demobilization of railway workers);
4. Single machine (one locomotive) 0 knots
The standard marshalling of passenger cars is 15 cars; The standard marshalling of freight cars is 70 cars
Passenger cars generally include 1 air-conditioned generator car, 6 hard seats, 1 dining car, 1 soft sleeper, 5 hard sleepers and 1 luggage car
An ordinary passenger car has 12 carriages, each of which is 16m long and 2.5m wide. The whole train has 1440 seats, If it is full of passengers, how much space does each passenger occupy on average?
A carriage is 16m long × 2.5m × 2.5m = 100m ^ 3 multiplied by 12 sections, a total of 1200m ^ 3 1200m ^ 3 is allocated to 1440 seats, and one seat accounts for 5m ^ 3 in 6
Grade 6 univariate equation During the Spring Festival, an extracurricular practice group of a middle school went to supermarkets A and B to investigate the sales situation. After the investigation, Mingming, Lili and Honghong communicated. According to their dialogue, please find out the sales of supermarkets A and B during the Spring Festival this year? Mingming: the sales of the two supermarkets were 1.5 million yuan last year and 1.7 million yuan this year Lili: the sales of supermarket a increased by 15% this year over last year Honghong: the sales of supermarket B increased by 10% this year over last year
Suppose that the sales of supermarket a last year was x million yuan, then supermarket B was 1.5-x million yuan
（1+15%）X+（1+10%）（150-X）=170
160+0.05X=170
0.05X=5
X=100
Supermarket B had sales of 500000 yuan last year
Fourth grade elementary school monadic equation exercises, But the more equations, the better
1、 Multiple choice questions:
1. In the following formulas, the equation of one variable and one degree is ()
A.1/2X-1=4/5-y B.-5-3=-8
C.X+3 D.X+4-3X/465=X+1
2. The solution of the equation is ()
A.-1/3 B.1/3 C.1 D.-1
3. If the solution of the equation about satisfies the equation, the value of is ()
A.10 B.8 C.-10 D.-8
4. The following equation is correct according to its nature ()
A. from - 1 / 3x = 2 / 3Y, x = 2Y; B. from 3x-2 = 2x + 2, x = 4
C. from 2x-3 = 3x, get x = 3 d. from 3x-5, get 3x = 7-5
5. When solving equation 2x + 1 / 3-10x + 1 / 6 = 1, after removing the denominator, the correct result is ()
A.4X+1-10X+1=1 B.4X+2-10X-1=1
C.4X+2-10X-1=6 C.4X+2-10X+1=6
6. The price of TV sets has been reduced by 10% for two consecutive times. After the price reduction, the price of each TV set is a yuan, then the original price of the TV set is ()
A.0.81a yuan b.1.21a yuan c.a/1.21 yuan d.a/0.81 yuan
2. Fill in the blanks:
1l2xl = 4, x then ___
2. If the square of lx-y + 4L + (Y-3) is known to be 0, then 2x + y = _____
3. If the solution of equation 2 (x-1) - a = 0 of X is 3, then the value of a is _______
4. There is a three digit number, the single digit is a, the number on the tenth digit is B, and the number on the hundred digit is C, then the three digits are expressed as ___
5. There are 96 students in class A and class B. class A has 2 more students than class B, so class B has________ People
6. 3 times of a certain number is 2 times larger than half of it. If a certain number is y, the equation is _
7. When___ The values of algebraic expressions 4x + 2 and 3x-9 are opposite to each other
III. solving equation:
1、2(X-1)=4 2、1/2(1/2X-1)-1=1
3、 1-3(8-X)=-2(15-2X) 4、 X+1/2+X-4/3=2
IV. application problems of solving equations:
1. The enemy fled at the station 8 kilometers away from our army. The time was 4 a.m. our army started at 5 a.m. and pursued at the speed of 10 kilometers per hour. As a result, we caught up at 7 a.m. what was the speed of the enemy when he fled?
2. During the mid-term examination, the information technology teacher limited 40 minutes and asked each seventh grade student to type an article. It is known that it takes 50 minutes for Xiaobao to type an article of the same size independently, and only 30 minutes for Xiaobei. In order to complete the task, Xiaobao played for 30 minutes and asked Xiaobei for help and cooperation. Can he finish it within the required time?
3. The mother of the black bear wanted to test the effect of the little bear's learning "solving application problems by equations". She gave the little bear 19 apples and asked the little bear to divide them into four piles. After the score, if the first pile is doubled, the second pile is increased by one, the third pile is reduced by two, and the fourth pile is doubled, the number of apples in these four piles will be the same again. The little bear takes his head, how to divide these 19 apples into four piles?
4. The school is going to spend 2000 yuan to buy prizes for 22 winners of the "Hope Cup" competition. The first prize is 200 yuan per person and the second prize is 50 yuan per person. How many students are seeking to win the first prize and the second prize respectively?
Excuse me: what grade does Tianjin primary school offer English classes from?
Third grade, officially from third grade, my relatives' children also have their school age 1, but they are interest classes
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