1. To transport 29.5 tons of coal, transport it three times by a truck with a load of 4 tons, and transport the rest by a truck with a load of 2.5 tons. How many times will it take to complete? It takes x times to complete 29.5-3 * 4 = 2.5x17.5 = 2.5xx = 7. 2. The trapezoidal site covers an area of 90 square meters, with an upper bottom of 7 meters and a lower bottom of 1 1 meter. How high is it? Its height is x m x (7+11) = 90 * 218x =180x =10. Its height is 10 m3. A workshop plans to produce 5480 parts in April. It has been in production for 9 days, and there are 908 more to complete the production plan. How many pieces will be produced on average every day in these 9 days? In these nine days, the average daily output is X 9x+908=5408 9x=4500 x=500. During these nine days, an average of 500 were produced every day. 4. The two cars of Party A and Party B walked in opposite directions at the same time from two places 272km apart. After three hours, the distance between the two cars was still17km. A travels 45 kilometers per hour, and B travels how many kilometers per hour? B travel x kilometers per hour (45+x)+17 = 272 3 (45+x) = 255 45+x = 85 x = 40 b travel 40 kilometers per hour. 5. There are two classes in grade six in a school, and the average score of mathematics last semester is 85. There are 40 students in six classes (1) with an average score of 87. 1. There are 42 students in Class Six (2). What is the average score? The average score is 40 * 87.1+42x = 85 * 82 3484+42x = 6970 42x = 3486x = 83. 6. The school bought 10 boxes of chalk, used 250 boxes, and left 550 boxes. How many boxes are there in each box? On average, there are10x = 250+55010x = 800x = 80 cases per case. There are 200 students in Grade 7 and Grade 4. During extracurricular activities, 80 girls jumped rope. The boys are divided into five groups to play football. How many people are in each group? The average number of people in each group is 5x+80 = 200x = 160x = 32. The average number of people in each group is 32. 8. The canteen brought 150 kg of rice, which was 30 kg less than the flour. How many kilograms of flour does the canteen send? Flour in the canteen x kg 3x-30 =150 3x =180 x = 60 flour in the canteen 60 kg 9. There are 52 peach trees and 6 rows of pear trees in the orchard. There are 20 more pear trees than peach trees. How many pear trees are there in each row on average? There are x pear trees in each row, 6x-52=20 6x=72 x= 12. There are 12 pear trees in each row on average. The area of a triangular plot is 840 square meters, the bottom is 140 meters, and the height is how many meters? The height is x m140x = 840 * 2140x =1680x =12, and the height is 12m 1. Li Shifu bought 72m cloth and just made 20 adult clothes, 65438+. Adult dresses are 2.4 meters each, and how many meters are children's dresses? The fabric for children's wear is16x+20 * 2.4 = 7216x = 72-4816x = 24x =1.5. Mother was six times older than her daughter three years ago. My daughter is 30 = 6 (x-3) 6x-18 = 30 6x = 48 x = 8. Daughter is 8 years old. 13. How long will it take for a car traveling at 50 kilometers per hour to catch up with a car traveling at 40 kilometers per hour that left two hours ago? Need x time 50x=40x+80 10x=80 x=8 need 8 time 14. Xiaodong went to the fruit shop and bought 3 kilograms of apples and 2 kilograms of pears. * * He paid 15 yuan, 1 kg of apples is more expensive than 1 kg of pears in 0.5 yuan. How much are apples and pears per kilogram? Apple 3x+2 (x-0.5) =155x =16x = 3.2 Apple: 3.2 pear: 2.7 15. Two cars, A and B, start from A and B at the same time and face each other. A travels at a speed of 50 kilometers per hour, while B travels at a speed of 40 kilometers per hour. How many hours does it take for A to reach the midpoint? A reaches the midpoint in x hours 50x = 40 (x+1)10x = 40x = 4a reaches the midpoint in 4 hours 16. A and B leave from A and B at the same time, face to face, and meet in 2 hours. If A starts from place A and B goes in the same direction at the same time, then A will catch up with B after 4 hours. It is known that the speed of A is 15km/, and the speed of B is x2 (x+15)+4x = 602x+30+4x = 606x = 30x = 5b and 5 17. Two ropes with the same length, the first one was cut 15m, and the second one was 3m more than the remaining three times of the first one. How long are these two ropes? It turns out that the length of each of the two ropes is xm3 (x-15)+3 = x3x-45+3 = x2x = 42x = 21. Originally, the lengths of the two ropes were 2 1m and 18 respectively. A school bought seven basketballs and 10 football * * and paid 20 yuan. As we all know, the price of each basketball is equivalent to the price of three footballs. How much is basketball and football each? 7x+10x/3 = 248 21x+10x = 744 31x = 744x = 24 each basketball: 24 each football: 8 19, with 29.5 tons transported. How many times will it take to complete? It takes x times to complete 29.5-3 * 4 = 2.5x17.5 = 2.5xx = 7. 20. The trapezoidal site covers an area of 90 square meters, with an upper floor of 7 meters and a lower floor of 1 1 meter. How high is it? Its height is x m x (7+11) = 90 * 218x =180x =10. Its height is10m21. A workshop plans to produce 5480 parts in April. It has been in production for 9 days, and there are 908 more to complete the production plan. How many pieces will be produced on average every day in these 9 days? In these nine days, the average daily output is X 9x+908=5408 9x=4500 x=500. During these nine days, an average of 500 were produced every day. 22. Two cars, Party A and Party B, walk in opposite directions from two places 272km apart, and the distance between the two cars is still 17km after three hours. A travels 45 kilometers per hour, and B travels how many kilometers per hour? B travels at the speed of x km 3 (45+x)+17 = 272 3 (45+x) = 255 45+x = 85 x = 40 b travels at the speed of 40 km 2 3 per hour. There are two classes in grade six in a school, and the average score in mathematics last semester was 85. There are 40 students in six classes (1) with an average score of 87. 1. There are 42 students in Class Six (2). What is the average score? The average score is 40 * 87.1+42x = 85 * 82 3484+42x = 6970 42x = 3486x = 83. The school bought 10 boxes of chalk. 250 boxes were used, and there are 550 boxes left. How many boxes are there in each box? X boxes10x = 250+55010x = 800x = 80 on average. There are 200 students in grades 25 and 4. During extracurricular activities, 80 girls jumped rope. The boys are divided into five groups to play football. How many people are in each group? The average number of people in each group is 5x+80 = 200x = 160x = 32, and the average number of people in each group is 32. 26. The canteen brought 150 kg of rice, which was 30 kg less than the three times of flour. How many kilograms of flour does the canteen send? Flour in canteen x kg 3x-30 =150 3x =180 x = 60 flour in canteen 60 kg 27. There are 52 peach trees in the orchard with 6 rows of pear trees, and there are 20 more pear trees than peach trees. How many pear trees are there in each row on average? There are x pear trees in each row, 6x-52=20 6x=72 x= 12. There are 12 pear trees in each row on average. 28. The area of a triangular plot is 840 square meters, the base is 140 meters, and the height is how many meters? The height is x m140x = 840 * 2140x =1680x =12, and the height is 12m 29. Li Shifu bought 72m cloth and just made 20 adult clothes and 16 children's clothes. Adult dresses are 2.4 meters each, and how many meters are children's dresses? Children's clothing16x+20 * 2.4 = 7216x = 72-4816x = 24x =1.5. Each piece of cloth for children's wear is1.5m. Three or three years ago, my mother was six times her daughter's age. This year, my mother is 33 years old. My daughter is 30 = 6 (x-3) 6x-18 = 30 6x = 48 x = 8. Daughter 8 years old 3 1. How long will it take for a car traveling at 50 kilometers per hour to catch up with a car traveling at 40 kilometers per hour that left two hours ago? It takes x time 50x=40x+80 10x=80 x=8, and it takes 8 times 32. Xiaodong went to the fruit shop and bought 3 kilograms of apples and 2 kilograms of pears. * * * Paid 15 yuan, 1 kg of apples is more expensive than 1 kg of pears in 0.5 yuan. How much are apples and pears per kilogram? Apple 3x+2 (x-0.5) =155x =16x = 3.2 Apple: 3.2 Pear: 2.7 33. Two cars, A and B, start from A and B at the same time and travel in opposite directions. A travels 50 km/h, B travels 40 km/h, A travels 65438 earlier than B, and how many hours does it take for A to reach the midpoint? X hours reach the midpoint 50x = 40 (x+1)10x = 40x = 4 hours reach the midpoint 34. A and B leave from A and B at the same time, face to face, and meet in 2 hours. If A starts from place A and B goes in the same direction at the same time, then A will catch up with B after 4 hours. Given that the speed of A is 15km/, find the speed of B. The speed of B x2 (x+15)+4x = 602x+30+4x = 606x = 30x = 5b's speed 5 35. Two ropes with the same length, the first one was cut 15m, and the second one was 3m more than the rest. How long are these two ropes? It turns out that the length of each of the two ropes is xm3 (x-15)+3 = x3x-45+3 = x2x = 42x = 21. It turns out that the length of each of the two ropes is 2 1 m3. A school bought seven basketballs and 10 soccer balls, and paid 248 yuan. As we all know, the price of each basketball is equivalent to the price of three footballs. How much is basketball and football each? Each basketball 7x+10x/3 = 248 21x+10x = 744 31x = 744x = 24 each basketball: 24 each football: 8 37, carrying a batch of goods, renting these two big trucks twice: the first. 15.5 tons. Class II A cars, Class V B cars and 6 cars have transported 35 tons of goods. Now we rent three A-class cars and five B-class cars from this company. If the freight is paid per ton, 30 yuan asks the owner how much: A can load X tons, and B can load Y tons. Then 2x+3y= 15.5 5x+6y=35, x=4 y=2.5, (3x+5y)*30=735 38. Now the price of a commodity is reduced by 10%. In order to keep the total sales amount unchanged, how much is the sales volume increased over the original price? Solution: increase the original price by x% (1-10%) * (1+x%). =1x% =111%In order to keep the total sales amount unchanged, the sales volume increased by 1 1. 1% 39 and 65439. Solution: Let the original price be X yuan (1-10%) X-40 = 0.5xx = 100 A: The original price is100 yuan 40, and there are 40 grams of salt water with 8% salt content. How many grams of salt should be added to make the salt water contain 20% salt? Solution: Assuming that the pure salt is 40*8% when X grams of salt is added, and its concentration is 20% when X grams of salt is added, then (40*8%+x)/(40+X) = 20% (3.2+X)/(40+X). =0.2 3.2+x=8+0.2x 0.8x=4.8 x=6, so add 6 grams of salt, 4 1, transport 29.5 tons of coal, transport it three times by a truck with a load of 4 tons, and transport the rest by a truck with a load of 2.5 tons. How many times will it take to complete? It takes x times to complete. 29.5-3× 4 = 2.5x17.5 = 2.5xx = 7 A: It takes seven times to complete. 42. The trapezoidal site covers an area of 90 square meters, with an upper floor of 7 meters and a lower floor of 1 1 meter. How high is it? Solution: Its height is x m x (7+11) = 90 * 218x =180x =10. Its height is10.43 meters. A workshop plans to produce 5480 parts in April. It has been in production for 9 days, and there are 908 more to complete the production plan. How many pieces will be produced on average every day in these 9 days? In these nine days, the average daily output is X 9x+908=5408 9x=4500 x=500. During these nine days, an average of 500 Model 44 cars were produced every day. Two cars, Party A and Party B, walked in opposite directions from two places 272km apart, and after three hours, the distance between the two cars was still17km. A travels 45 kilometers per hour, and B travels how many kilometers per hour? B Drive at an hour of X Km3 (45+X)+17 = 272 3 (45+X) = 255 45+X = 85 X = 40 B at an hour of 40 Km3. There are two classes in grade six in a school, and the average score in mathematics last semester was 85. There are 40 students in six classes (1) with an average score of 87. 1. There are 42 students in Class Six (2). What is the average score? The average score is 40 * 87.1+42x = 85 * 82 3484+42x = 6970 42x = 3486x = 83. The school bought 10 boxes of chalk. 250 boxes were used, and there are 550 boxes left. How many boxes are there in each box? X boxes10x = 250+55010x = 800x = 80 on average. There are 200 students in grades 47 and 4. During extracurricular activities, 80 girls jumped rope. The boys are divided into five groups to play football. How many people are in each group? The average number of people in each group is 5x+80 = 200x = 160x = 32, and the average number of people in each group is 32. 48. The canteen brought 150 kg of rice, which was 30 kg less than the flour. How many kilograms of flour does the canteen send? Flour in canteen x kg 3x-30 =150 3x =180 x = 60 flour in canteen 60 kg 49. There are 52 peach trees and 6 rows of pear trees in the orchard. There are 20 more pear trees than peach trees. How many pear trees are there in each row on average? There are x pear trees in each row, 6x-52=20 6x=72 x= 12. There are 12 pear trees in each row on average. The area of a triangular plot is 840 square meters, the bottom is 140 meters, and the height is how many meters? The height is x m140x = 840 * 2140x =1680x =12, and the height is 12m 5 1. Li Shifu bought 72m cloth and just made 20 adult clothes and 16 children's clothes. Adult dresses are 2.4 meters each, and how many meters are children's dresses? Children's clothing16x+20 * 2.4 = 7216x = 72-4816x = 24x =1.5. Children's clothing per cloth 1.5m 52, 3 years ago, my mother was 6 times older than my daughter. This year, my mother is 33 years old. My daughter is 30 = 6 (x-3) 6x-18 = 30 6x = 48 x = 8. Daughter is 8 years old and 53 years old. How long will it take for a car traveling at 50 kilometers per hour to catch up with a car traveling at 40 kilometers per hour that left two hours ago? Need x time 50x=40x+80 10x=80 x=8 need 8 time 54. Xiaodong went to the fruit shop and bought 3 kilograms of apples and 2 kilograms of pears. * * He paid 15 yuan, 1 kg of apples is more expensive than 1 kg of pears in 0.5 yuan. How much are apples and pears per kilogram? Apple 3x+2 (x-0.5) =155x =16x = 3.2 Apple: 3.2 Pear: 2.7 55. Two cars, A and B, set off from A and B at the same time, heading in opposite directions, with A traveling at 50 kilometers per hour, B traveling at 40 kilometers per hour, and A traveling 6545 ahead of B. A reaches the midpoint 50x = 40 (x+1)10x = 40x = 4a within x hours and reaches the midpoint 56 within 4 hours. A and B leave from A and B at the same time, face to face, and meet in 2 hours. If A starts from place A and B goes in the same direction at the same time, then A will catch up with B after 4 hours. Given that the speed of A is 15km/, find the speed of B. The speed of B x2 (x+15)+4x = 602x+30+4x = 606x = 30x = 5b's speed 5 57. Two ropes with the same length, the first one was cut 15m, and the second one was 3m more than the rest. How long are these two ropes? It turns out that the length of each of the two ropes is xm3 (x-15)+3 = x3x-45+3 = x2x = 42x = 21. It turns out that the length of each of the two ropes is 2 1 m 58. A school bought seven basketballs and 10 soccer balls, and paid 248 yuan. As we all know, the price of each basketball is equivalent to the price of three footballs. How much is basketball and football each? Each basketball 7x+10x/3 = 248 21x+10x = 744 31x = 744x = 24 each basketball: 24 each football: 8 59, transporting 29.5 tons of coal, and transporting it by a truck with a load of 4 tons. How many times will it take to complete? It takes x times to complete 29.5-3 * 4 = 2.5x17.5 = 2.5xx = 7. 60. The trapezoidal site covers an area of 90 square meters, with an upper floor of 7 meters and a lower floor of 1 1 meter. How high is it? Its height is x m x (7+11) = 90 * 218x =180x = 10, and its height is10 m.