An equation with unknowns is called an equation. Is that right?

An equation with unknowns is called an equation. Is that right?

wrong
The equation is the equation
An equation with unknowns is called an equation

An equation is an equation with unknowns______ (judge right or wrong)

Equation refers to the equation containing unknowns. This sentence is in line with the meaning of equation, so it is correct

Judge that the equation with unknowns may be an equation

Right. 1. An equation must be an equation, but an inequality is also an equation, and an inequality is not an equation
2. If it is an equation with unknowns, the coefficient of unknowns is not zero
For example: (2-2) x + 1 = 1 is not an equation

Finding the derivative of function y = X-1 / X at x = 1

y'=[x-(x-1)]/x²=1/x²
Then the derivative of function y at x = 1 is y '(1) = 1

Kneeling for people's education press fifth grade volume II mathematical oral calculation, off form calculation, application problems, a little more

A workshop can produce 120 class a parts, or 100 class B parts, or 200 class C parts every day. Three, two, and one of class A, B, and C parts can be made into a set. Now it is required to produce the most complete sets of products within 30 days. How many days should class A, B, and C parts be produced?
1、 One step addition and subtraction of decimals
1. A math book costs 6.25 yuan, and a Chinese book costs 5.86 yuan. How much are the two books altogether?
2. A watermelon weighs 4.86 kg and a Hami melon weighs 3.5 kg. How many kg more does a watermelon weigh than a Hami melon?
One step multiplication and division of two decimals?
2. A sericulture professional group raises 21 spring silkworms, with a total cocoon yield of 1240 kg. How many kg of cocoon does each group produce on average?
3、 Xiao Hong read a story book for 5 days, 12 pages a day, and 38 pages a day. How many pages are there in this book? (draw a line diagram)
2. Each bag of flour weighs 25 kg, and each bag of rice weighs 50 kg?
3. The militiamen used 250 bullets for the first time, 320 bullets for the second time, and 180 fewer bullets for the third time than the sum of the previous two times. How many bullets for the third time?
4、 Two step calculation problems with two known conditions
1. The school bought 45 boxes of colored chalk, 15 boxes more white chalk than colored chalk. How many boxes of chalk do you buy altogether?
2. An empty basket weighs 2kg. Put 32kg peanuts into the basket. How many times is the weight of the basket with peanuts?
5、 Practical problems of tandem
1. Two carts of flour are delivered by the grain store, each containing 80 bags of 25kg. How many kilograms of flour are delivered by this grain store? (answer in two ways)
2. Third grade students to the garden to collect cabbage, divided into four groups, 11 people in each group, an average of 45 kg per person. How many kg of cabbage do you collect?
1. The chemical fertilizer plant plans to produce 7200 tons of chemical fertilizer. It has been producing for four months, with an average of 1200 tons of chemical fertilizer per month, and the remaining 800 tons per month. How many months will it take to complete the production?
2. The plastic factory plans to produce 1300 pieces of plastic moulds, 780 pieces in six days. According to this calculation, how many days will it take to complete the rest?
3. Master Li produced 252 parts in 4 hours in the morning, and worked for 3 hours in the afternoon at this speed. How many parts did Master Li produce in one day?
4. The cement plant plans to produce 3600 tons of cement, which will take 20 days to complete. The actual daily production is 20 tons more than the plan, how many days to complete the task?
5. A pile of 3.6 tons of coal can be burned for 10 days. After the improvement of the stove, 0.06 tons of coal can be saved every day compared with the original plan. How many days can this pile of coal be burned now?
6. The distance between Party A and Party B is 420 kilometers. A bus is planned to travel 7 hours from place a to place B. the actual distance is 10 kilometers more than the original plan. How many hours does it actually arrive?
7. Xiaoqiang goes back to school from home. If he walks 50 meters every minute and returns to school in 12 minutes, if he walks 10 meters more every minute, how many minutes in advance can he return to school?
8. Build a 6.4km long highway. In the first three months, build 1.2km per month on average, and the rest 1.4km per month. How many months will it take to complete?
9. Xiaoming used 10.2 yuan to buy Stationery, bought 6 pencils, each 0.45 yuan, the remaining money to buy ballpoint pens, each 2.5 yuan, how many can he buy?
10. The clothing factory originally planned to make 120 suits, each suit using 4.8 meters of cloth. After improving the cutting method, each suit can save 0.3 meters of cloth. How many suits can the original cloth make now?
11. For a story book, 576 words were arranged on each page and 25 pages were arranged. When it was reprinted, the characters were reduced to 18 pages. How many more words are arranged on each page now?
12. A passenger train and a freight train depart from Party A and Party B at the same time. The passenger train runs 80 kilometers per hour and the freight train 60 kilometers per hour. After five hours, the two trains meet. How long is the railway between Party A and Party B?
13. Two engineering teams open a 1500 meter tunnel at the same time. Engineering team a starts to dig 14 meters a day at one end, and engineering team B starts to dig 16 meters a day at the other end. How many days later can the tunnel be dug through?
14. Party A and Party B work together to type a manuscript of 7000 words at the same time. Party A will type 600 words per hour, and Party B will type 200 more words per hour than Party A. how many hours can we finish the task?
15. Xiaoming and Xiaoqiang walk in the opposite direction at the school gate after school. Xiaoming walks 70 meters per minute, Xiaoqiang walks 68 meters per minute. How many meters is the distance between them five minutes later?
16. The distance between a and B is 630 kilometers. Two hours after the bus leaves from a, the truck leaves from B. It is known that the bus runs 65 kilometers per hour and the truck runs 60 kilometers per hour. How many hours after the truck leaves, does it meet the bus?
Fifth grade mathematics practical exercises (2)
Class: Name: grade:
1. The machine tool factory originally knew that each machine tool used 1.02 tons of steel. After the improved design, each machine tool saved 0.12 tons compared with the original one. How many machine tools can be manufactured with the steel used for 300 machines?
2. Xiao Ming bought 6 pencils and 4 exercise books, each exercise book is 0.68 yuan, each pencil is 0.24 yuan. Xiao Ming paid 5 yuan, how much should he get back?
3. Train a and train B leave from the two places at the same time. Train a runs 80 kilometers per hour, while train B runs 70 kilometers per hour. After 12 hours, the two trains are still 110 kilometers apart. How many kilometers are there between the two places?
4. Guangming paper mill produced a batch of newsprint, which was originally planned to be completed in 28 days, and needed to produce 12.5 tons per day. The production was completed three days ahead of schedule. How many tons more per day than the original plan?
5. Master Li produces a batch of parts, 126 parts in the first three days. According to this calculation, the production task will be completed in another 12 days. How many parts are there in total?
6. The chemical fertilizer plant plans to produce 84 tons of chemical fertilizer in 30 days. The actual daily production is 0.2 tons more than the plan. How many days ahead of schedule can the task be completed?
7. Processing a batch of clothing, 300 sets per day, can be completed in 16 days,
(1) If you process 400 sets a day, how many days in advance?
(2) How many days can we finish if we process 20 more sets every day?
(3) If it is to be finished 5 days in advance, how many sets should be processed every day?
8. A car factory plans to produce 16800 cars in the whole year. As a result, the production task of the whole year is completed two months in advance. At this speed, how many cars can be produced in the whole year?
9. Xinfeng agricultural machinery factory processes 2480 parts in a workshop. Originally, it processes 100 parts a day. After 20 days, it processes 120 parts a day instead. In this way, it can complete the task in a few more days?
10. A clothing factory used to make a kind of children's clothing with 2.2 meters of cloth for each set. Now it improves the cutting method and saves 0.2 meters of cloth for each set. How many sets of cloth can be made for 600 sets of this kind of clothing?
11. Xiaohong bought three exercise books and three new word books, each of which costs 0.36 yuan for an exercise book and 0.32 yuan for a new word book. How much less does Xiaohong spend on new word books than on exercise books?
12. Students carry water to water the trees. In the third grade, 45 trees are watered. In the third grade, 10 trees are watered less than in the fourth grade. In the fourth grade, half of the trees watered in the fifth grade are watered. How many trees are watered more in the fifth grade than in the third grade?
13. The first team opened 12.6 meters a day, and the second team opened 14.4 meters a day. The first team opened five days later, and the second team joined. In another 21 days, the tunnel was finally opened
(1) How long is the tunnel?
(2) How many meters did the two teams dig when they got through?
14. Cars travel 63 kilometers per hour, and their speed is 1.4 times that of trucks. They travel from two places 270 kilometers apart at the same time and face each other
(1) After a few hours?
(2) How many kilometers did the two cars travel when they met?
(3) If the departure time is 8:15, what time is the meeting time?
1. A motorcycle can travel 98 kilometers per hour, and a truck can travel 80 kilometers per hour
(1) Time ratio of motorcycle to truck;
(2) The distance ratio of motorcycles to trucks;
(3) The ratio of motorcycle speed to truck speed
A car has traveled 280 kilometers from a to B, 500 kilometers away
3. For a project, team a will complete it in 10 days and team B will complete it in 8 days. What is the ratio of work efficiency between team a and team B?
4. There are 40 students in class 5 (1), and 32 of them have reached the standard of physical exercise. What percentage of the students who fail to reach the standard account for the whole class?
Xiao Li, Xiao Zhao and Xiao Wang work together to make a batch of parts. When they are finished, Xiao Li, Xiao Zhao and Xiao Wang work together to find the ratio of the total number of parts
In the first mathematics test of class 65 (1), 48 students passed and 2 students failed
There are 38 workers on duty and 2 absent in a workshop
8. A factory completed 56% of the planned output in the first half of the month and 64% of the planned output in the second half of the month. What is the increase rate this month?
9. The unit price of a self-taught series is 160 yuan, which is 40 yuan lower than the original price. How much is the current price?
There were 360 trees planted in spring and 440 trees planted in autumn, and 760 trees survived
The November moon cake factory produced 140 tons of moon cakes last year and 210 tons this year. How much more than last year?
How many percent more than 5 kg? How many percent less than 6 kg?
A factory completed 56% of the planned output in the first half of the month and 64% of the planned output in the second half of the month. What is the increase rate this month?
14. The planned number of garments produced in the second half of the year is 20% higher than that in the first half of the year. What percentage of the planned number of garments produced in the second half of the year is that in the first half of the year?
15. The oil yield of rapeseed is 38%. How many tons of oil can be produced from 5 tons of rapeseed?
16. To build a waterworks, the planned investment is 5 million yuan, which is 5% less than the plan. How many million yuan has been saved?
17. The oil yield of rapeseed has reached 85%. Eight hectares of rapeseed have been planted in diligent village, and 3750 kg of rapeseed have been received per hectare. How many kg of rapeseed oil can be produced?
18. There are 200 sixth grade students in Xinzhuang primary school, 120 of whom participate in the interest group. How many more people need to participate in order to make the number of students in the interest group reach 88%?
19. The chicken farm raised 100000 broilers, which were sold for the first time and 25% for the second time. How many thousands were left?
20. A pile of coal weighs 120 tons. It takes 20% of the total weight on the first day and 25% of the total weight on the second day. How many tons are left?
21. A car used to use 12 liters of gasoline per hour, but it saved 10% after repair. Now how many liters of gasoline does this car use per hour?
22. There are 120 students in the fourth grade of a primary school. Who is in the fifth grade? 0%. How many students are in the fifth grade?
23. The speed of a motorcycle is 70% faster than that of a car. How many kilometers can a motorcycle travel per hour?
24 a highway, the first month to build a full-length, the second month to build 6 kilometers, the remaining 37.5% did not build. How many meters of this highway length?
A factory produces a batch of parts, 40 pieces in the first day, 10% more in the second day than in the first day, and the output in two days accounts for 25% of the total. How many pieces are there in this batch of parts?
twenty-six