Example: Two trains run in opposite directions from two places 536 kilometers apart at the same time and meet four hours later. The local train is 60 kilometers per hour. How many hours is the express train?

Scheme 1: 4-hour express +4-hour slow train = total distance.

Solution: the speed of the express train is x kilometers per hour.

4X+60×4=536

4X+240=536

4X=296

X=74

Solution 2: (X+60)×4=536

X+60=536÷4

X= 134-60

X=74

A: The express train runs 74 kilometers per hour.

practice

(1) The parachute falls from18000m at a speed of10m per second. At the same time, a hot air balloon rose from the ground. Twenty minutes later, the parachute balls met in the air. How many meters does the hot air balloon rise per second?

(2) Two water inlet pipes, A and B, inject water into a water tank that can hold 8 tons of water. A tube injects 400 kilograms of water every minute. How many kilograms per minute can B pipe fill the pool in 8 minutes?

(3) The distance between the two places is 600 kilometers, and passenger and cargo vehicles start from both places at the same time. The bus travels 70 kilometers per hour and the truck travels 80 kilometers per hour. How many hours do two cars meet?

The distance between the two places is 249 kilometers, and a train runs from A to B at a speed of 55 per hour. 5 kilometers, how many hours have you walked, and there are still 27 kilometers to B?

⑤ Buy 5 notebooks and 3 pencils at a cost of 10.4 yuan. How much is a known pencil 0.9 yuan per notebook?

⑥ The clothing factory made 120 sets of 984 clothes. /kloc-how many sets will be made every day for the rest of 0/2 days?

⑦ Nine workers in a production team have to produce 1926 parts, and each person can produce 20 parts per hour. After working for 5.5 hours, the remaining tasks must be completed within 4 hours. How much must everyone produce per hour?

⑧ The motor factory plans to produce 65,438+0,980 motors, and has produced 45 motors every day for four consecutive days. Due to the improvement of technology, the output of 1.5 motors will be increased every day. How many days does it take to actually complete the task?

Second, the equation is established with the total amount as the equivalent relationship.

Example: There are 6,800 bales of grain in two granaries, A and B. A is three times as much as B. How many bales are there in each granary?

Solution: Warehouse B has X bales of grain, so Warehouse A has 3 bales of grain.

Number of packages in granary A+number of packages in granary B = total number of packages in granary B.

X+3X=6800

4X=6800

X= 1700

3X=3× 1700=5 100

Inspection: 1700+5 100=6800 packages (total number of packages in warehouses A and B).

Or 5 100÷ 1700=3 (warehouse a is three times that of warehouse b).

Answer: A raw grain is 5 100, and B raw grain is 0 1700.

practice

The school bought a table tennis ball and a blue ball *** 135, and the table tennis ball bought was 8 times that of the blue ball. How many balls are there?

(2) There is an upper and lower bookshelf with 240 books in it. There are twice as many books on the upper shelf as on the lower shelf. How many books are there on each shelf?

(3) The library purchased 235 books on literature and art, and the number of books on literature and art was twice that of books on science and technology, with 25 books. How many books did you each buy?

(4) Party A, Party B and Party C donated money to the disaster area ***270 yuan. Party A's donation is three times that of Party B and twice that of Party C. How much did they each donate?

⑤ The distance between Wharf A and Wharf B is 379.4 kilometers, and the speed of Ship A is 3.6 kilometers faster than that of Ship B, and the two ships are facing each other at the same time. Three hours after the departure, the distance between the two ships is still 48.2 kilometers. What is the speed of the two ships?

Thirdly, the equation is established by taking the phase difference as the equivalent relationship.

For example, the chemical fertilizer plant used 420 tons of water in March and 380 tons in April, which saved more water than in March. How much is 60 yuan to pay for these two months?

Solution: the water fee per ton is X yuan.

Water fee in March = water fee saved in April.

420X-380X=60

40X=60

X= 1.5

Water fee paid in March 1.5×420=630 (RMB).

The water fee paid in April is 1.5×380=570 (RMB).

Answer: 630 yuan pays the water fee in March and 570 yuan pays the water fee in April.

Exercise:

① Xinhua Bookstore sells 90 packages of Class A books and 68 packages of Class B books. There are more type A books than type B books 1 100. How many are there in each package?

② A basket of apples is 30 kilograms heavier than a basket of pears, and the number of kilograms of apples is 2.5 times that of pears. How many kilograms are apples and pears?

(3) Two square plots, the side length of the first plot is twice that of the second plot, and their perimeters are 56 cm apart. What are the side lengths of these two plots?

(4) Liang Xiao bought ***20 pieces from each 0.5 yuan and each 1.2 yuan, and paid 20 yuan to find 4.4 yuan. How many pens did he buy?

⑤ The difference between the numbers A and B is 100, and the number A is four times more than the number B. How to find the numbers A and B?

6. Two pools * * * store 60 tons of water, and pool A uses 6 tons. After 8 tons of water was injected into Pool B, the water in Pool B was 4 tons less than that in Pool A. How many tons were stored in the two pools?

⑦ Master and apprentice are processing a batch of parts at the same time. The apprentice made 30 parts a day, but the master only made 6 days because of something, 3 days less than the apprentice and 12 more parts than the apprentice. How many parts does the master make every day?

The cabbage bought in the canteen is 20 kg less than the radish, and the radish is 70 kg less than the cabbage. How many Jin did you buy in the Chinese cabbage and radish canteen?