A mathematical problem of finding rules in grade one of junior high school Example: 1 / 1 × 2 = 1-1 / 2 1 / 2 × 3 = 1 / 2-1 / 3 Calculation: 1 / 1 × 3 + 1 / 3 × 5 + 1 / 5 × 7 + 1/99× 101=?

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• 1. Write three different formulas with negative 6 3 4 10 so that the result is equal to 24
• 2. Xiaoming and Xiaojun have 52 cards in total, and the number of Xiaoming's cards is two times that of Xiaojun's. how many cards do they each have?
• 3. It takes 10 hours for the passenger car to complete the whole journey, 12 hours for the freight car to complete the whole journey, and 5 hours for the two cars to leave each other How many kilometers is the distance between the two cities It's 50 kilometers in five hours
• 4. A company organized a group outing. Eight people rushed to the railway station by two cars. One of the cars broke down 15 km away from the railway station. At this time, there is still 42 minutes to stop the train checking in. At this time, only one car can be used, or they can walk. The average speed of the car is 60 km / h, and the walking speed is 5 km / h, Can all eight of them catch the train? (1) Can all the eight people catch up with the train if they can get back and forth by this car alone (2) Please come up with two plans to make these eight people catch the train (regardless of other factors)
• 5. What is the biggest difference between beam bridge and arch bridge? Detailed description of stress characteristics? Urgent
• 6. Both Party A and Party B go from place a to place B. Party A walks 5km per hour, 1.5h first, and Party B bicycles for 50min. They arrive at place B at the same time, One is to set X kilometers per hour. Is there another solution? In the second method, the equation should not be set at the speed of X kilometers per hour
• 7. The total weight of two cases of apples is 20 kg. If 4 / 1 kg is taken out of the first case and put into the second case, the two cases of apples will have the same weight? Please
• 8. There are 500 kg apples in the fruit shop, just 1 / 9 more than pears. How many kg pears?
• 9. In the parallelogram ABCD, ad and BC are taken as sides respectively, and the equilateral △ ade and equilateral triangle BFC are made outside the parallelogram ABCD
• 10. Taking the adjacent sides AB and ad of the parallelogram ABCD as one side, we make an equilateral triangle ABF and ade outside the parallelogram, and prove that △ CEF is also an equilateral triangle
• 11. There is a series of numbers "1, 1, 1, 3, 5, 9, 17, 31, 57, 105." what is the remainder of the number 2011 divided by 3
• 12. It is known that "@" is a symbol ,2@3=2+3+4 ,7@2=7+8 ,3@5=3+4+5+6+7. According to the law of degree, if n + 8 = 68, then how much is n
• 13. 4000-5-10-15-...-95-100=?
• 14. A mathematical problem A company is planning to organize some employees to travel to Beijing in May. Now it has contacted two travel agencies, a and B. both travel agencies offer a price of 2000 yuan per person. At the same time, both travel agencies offer preferential measures to groups with more than 10 employees: a travel agency gives 25% discount to each employee; B travel agency exempts one leader from the cost of managing employees, and the rest employees get 20% discount (1) If there are a (a > 10) employees participating in the tour, the cost of travel agency a is () The cost of B travel agency is () yuan (2) If the company now organizes 20 employees including management staff to travel to Beijing, which travel agency will be more favorable for the company? Please explain the reason. (explain the reason) 3. If we plan to travel for seven days in May, let the date in the middle be a, then the sum of the dates of the seven days is () (expressed by an algebraic expression containing a and simplified) If the sum of these seven days is a multiple of 63, what date may they start on? (write down all the possibilities that meet the conditions, and write down the simple calculation process)
• 15. Quadratic inequality of one variable in high order 1. Find the solution set of the following inequality (1) 4x-4x > 15 (2) 13-4x > 0 (3) X-3x-10 > 0 (4) x (9-x) > 0 2. Find the domain of the following functions (1) Y = root x-4x + 9 (2) y = root - 2x + 12x-18 3. If there are two unequal real roots of the hospital quadratic equation x - (M + 1) x-m = 0 about X, find the value range of M 4. Given the set a = {x | x-160}, find a U B
• 16. The problem of solving quadratic inequality of one variable If the domain of kx2-6kx + (K + 8) under y = root is r, then the value range of K is r_____ [Note: 2 in kx2 is square, need to explain in detail]
• 17. How to solve the univariate quadratic inequality of senior one? 1. (x-1) (the square of x-3x + 2)
• 18. Two inequality problems 1. Real numbers x and y satisfy the inequality X-Y ≥ 0 and Y ≥ 0 and 2x-y-2 ≥ 0 Find the value range of W = Y-1 / x + 1 2. Sequence 3 / 2, 9 / 4, 25 / 8, 65 / 16161 / 32 N*1/2^n Finding the sum of the first n terms
• 19. Ask the master to solve the following inequality problem, remember that I am a freshman in high school 2x+3/x+2-1 /After that are molecules
• 20. How to solve these inequalities 1. |ax+3|0 3. (x-1)^2(x+2) ----------------0, (a belongs to R) Thank you!