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, and its height is10 m.
A workshop plans to produce 5480 parts in April. It has been produced for 9 days, and there are still 908 parts to complete the production plan. How many parts will be produced on average every day in these 9 days? During these nine days, the average daily output is X 9x+908=5408 9x=4500 x=500.
4. Two cars, A and B, are driving in opposite directions from two places 272 kilometers apart. Three hours later, the distance between the two cars is still 17 km. A travels 45 kilometers per hour, and B travels how many kilometers per hour? B drive x km 3 (45+x)+17 = 272 3 (45+x) = 255 45+x = 85 x = 40 b drive 40 km 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 6 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, and the average score is 83.
6. The school bought 10 boxes of chalk. 250 boxes were used, and there are 550 boxes left. How many boxes per box? The average number of X boxes per box is10x = 250+55010x = 800x = 80, with an average of 80 boxes per box.
There are 200 students in the fourth grade. During extracurricular activities, 80 girls jumped rope. The boys are divided into five groups to play football. How many people are there in each group on average? The average number of x people in each group is 5x+80 = 200x = 160x = 32, and 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 did the canteen deliver? Canteen flour x kg 3x-30 =150 3x =180 x = 60 canteen flour 60 kg.
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, and each row has 12 pear trees.
10, the area of a triangle 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.
1 1, Li Shifu bought 72 meters of cloth and just made 20 adult clothes and 16 children's clothes. Each adult dress is 2.4 meters, and how many meters is each child dress? Each children's clothing16x+20 * 2.4 = 7216x = 72-4816x = 24x = 1.5 each children's clothing1.5 meters.
12, three years ago, my mother was six times older than my daughter. This year, my mother is 33 years old. How old is my daughter? My daughter is 30 = 6 (x-3) 6x-18 = 30 6x = 48 x = 8. My daughter is 8 years old.
13. How long will it take for a car with a speed of 50 kilometers per hour to catch up with a car with a speed of 40 kilometers per hour that left two hours ago? It takes x time, 50x=40x+80 10x=80 x=8, and it takes 8 time.
14. Xiaodong bought 3 Jin of apples and 2 Jin of pears at the fruit shop and paid 15 yuan. 1kg apples are more expensive than 1kg 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, A and B start from A and B at the same time, respectively, in opposite directions. A travels 50 kilometers per hour, B travels 40 kilometers per hour, and A reaches the midpoint 1 hour earlier than B. How many hours does it take for A to reach the midpoint? A x hours reach the midpoint 50x = 40 (x+1)10x = 40x = 4a4 hours reach the midpoint.
16, Party A and Party B set out from A and B respectively at the same time, headed for the other side, and met two hours later. If A and B start from A and go in the same direction at the same time, then A will catch up with B after 4 hours. Given the vehicle speed of Party A as 15 km/h, the vehicle speed of Party B can be calculated, and the vehicle speed of Party B is x 2 (x+65433).
17. Two ropes with the same length, the first one was cut15m, and the second one was 3m more than the rest. How long are the original two ropes? Originally, the two ropes were Xm3 (x-15)+3 = x3x-45+3 = x2x = 42x = 21. It turns out that the two ropes are each 2 1 m long.
18. A school bought 7 basketballs and 10 football, 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 is 7x+10x/3 = 248 21x+10x = 744 31x = 744x = 24 each basketball: 24 each football: 8.
19. 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? X times completed 29.5-3 * 4 = 2.5x17.5 = 2.5xx = 7, 7 times completed.
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, and its height is10 m.