When is the addition and subtraction elimination method to use formula 1 minus formula 2? Yes or add formula 2? Or use formula 2 minus Formula 1?
Match the coefficients of an unknown number into the same, larger, smaller, or positive, depending on the actual situation
The method of adding, subtracting and eliminating elements for binary linear equation (when to add, when to subtract, how to add and how to subtract)
Basic properties of inequality?
Basic property 1: add or subtract the same integral on both sides of the inequality, and the direction of the inequality sign does not change,
Basic properties: both sides of the inequality multiply (or divide) the same integer greater than 0 at the same time, and the direction of the inequality sign does not change
Basic properties: both sides of the inequality multiply (or divide) the same integer less than 0 at the same time, and the direction of inequality sign changes
RELATED INFORMATIONS
- 1. The basic properties of inequality
- 2. The addition and subtraction of rational numbers can be unified into_____ The calculation is based on the method
- 3. Write down the steps for the first question. Don't write down the second question 1. A base angle of an isosceles triangle is equal to 4 times the vertex angle. Find the degree of each angle of the isosceles triangle 2. The difference between axisymmetric figures and axisymmetric figures is that the former is for () figures, while the latter is for () figures
- 4. Or a math problem about stocks 4} If A-share investors buy 1000 shares with 9 yuan on September 1, 2008 and 2000 shares with 5.60 yuan on November 3, 2008, when the P / E ratio of Angang shares reaches 2 times, how much is the interest of A-share investors? 5. What kind of psychological process did A-share investors go through to ensure the realization of the above four investment returns in the process of investment and operation? 1. If the price to book ratio of a stock is 0.8 times, what is the significance of 0.8 times price to book ratio? In 2008, the net asset of Anshan Iron and Steel Co., Ltd. was 7 yuan. In September 2008, the closing price of Anshan Iron and Steel Co., Ltd. was 9 yuan On March 3 and November 3, the closing price of Angang shares was 5.60 yuan. What is the price to book ratio at this time? These five questions are connected
- 5. In an enterprise, the former a shareholder accounts for 51.46%, B shareholder accounts for 32.66%, C shareholder accounts for 10%, D shareholder accounts for 5.88%. Now D shareholder wants to withdraw, and ABC three shareholders want to purchase D shareholder's shares according to their respective share proportion,
- 6. When a store goes to the apple producing area to buy apples, the purchase price is 1.2 yuan per kilogram. The distance from the producing area to the store is 400 kilometers, and the freight is 1.5 yuan per ton of goods. If the loss in the process of transportation and sales is 10%, in order to achieve a 25% profit margin, how much yuan per kilogram should the retail price be? A bookstore sells a kind of calendar. It can make a profit of 18 yuan for each calendar sold. After 2 / 5 of the calendar is sold out, the price of each calendar is reduced by 10 yuan, and the total profit is 3000 yuan?
- 7. 1. Tear a piece of paper into four small pieces for the first time, and then prick one of them into four smaller pieces each time. If we go on like this, can we tear the film into 2007 pieces according to this tearing method? Why? 2. 128 soldiers were arrested. The enemy ordered them to form a circle and number 1.2.3.4.128. The enemy killed No. 1 and No. 3 first. They killed one by one. They killed one by one in this way. At last, there was one person left, Joseph. What's the number of Joseph? 3. There are three good friends. One is three years older than the other. The product of their ages is 1620. What is the sum of their ages?
- 8. 37 is a multiple of 3 at least if you add [] to it. At least if you add [] to it, it is a multiple of 2 and 5 at the same time
- 9. Primary school mathematics problem solving.. a total of 6 problems to step, thank you o (∩)_ ∩)o 1)240 *(3/4 45%) 2) 9/14 * 25% 3) 5/14 * 1/4 4)1/2X - 35%x= 12 5) 34% divided by 4x = 1 / 2 6) 80%x - 1/2x = 1 Give me the steps~~~~~~~~~~~~~
- 10. (1) Cut a cone along its height and get two objects. The cross-sectional area is 10 square centimeters. If the cone is 5 centimeters high, what is its bottom area in square centimeters? What is its volume in cubic centimeters? (2) A cylindrical bucket with a bottom inner radius of 30cm contains some water. Immerse a conical part with a bottom radius of 10cm in water. When the part is taken out of the water, the water in the bucket drops by 5cm. What is the volume of the part in cubic centimeter? (3) There are two parts of the same material, one weighs 1068 grams, the volume is 120 cubic centimeters, and the other weighs 756.5 grams. What's its volume? (4) In order to measure the volume of radish, Master Wang first cut a radish into a cuboid which is 5cm long, 4cm wide and 2cm high. Then he measured the weight of the cuboid with a scale of 20g. Then he measured the weight of the radish with a scale of 320G. How many cubic centimeters is the volume of the radish? (5) Uncle Li piles some rice in the corner. The shape is cone. Do you have a way to measure the volume of rice? Please design a feasible measurement scheme first, and calculate the volume of rice by assuming the required data (6) Find an old light bulb and find a way to measure its volume. Write down your measurement results (all questions should be able to understand, formula and equation are OK!
- 11. Who has a calculator for time addition and subtraction? Find a calculator that can calculate the time addition and subtraction method, for example: it's 13:57 now, work out what time is 11 hours and 29 minutes later
- 12. Give three integers: A2, B2 and 2Ab. Choose any two integers to add or subtract, so that the resulting polynomial can be factorized. Please write down your selected formula and factorize. (one is enough)
- 13. Let m = (x = a + B radical 2, A.B belongs to q), the experiment proves that M is closed for addition, subtraction, multiplication and division
- 14. If two vectors are collinear, why is x1y2-x2y1 equal to zero?
- 15. When are two vectors, x1y2 = x2y1
- 16. Let a = (x1, Y1) and B = (X2, Y2), then the following is a necessary and sufficient condition for a and B to be collinear: there exists a Let a = (x1, Y1) and B = (X2, Y2), then the following are the necessary and sufficient conditions for a and B to be collinear: a = (x1, Y1) and B = (X2, Y2) ① There is a real number λ, such that a = λ B or B = λ a, why is it right
- 17. Vector product operation of vector? Note: the following letters are all vectors, except K, where x is cross product M = 2A + B N = Ka + B │ a │ = 1 │ B │ = 2 a ⊥ B Q: when k is the value, the area of parallelogram with m and N as adjacent sides is 6 │ m × n │ = (2a + b) × (KA + b) │ = (2 + k) * a × B │ = │ 2 + K │ a × B │ = 2 │ 2 + K │ = 6 to get k = 1 or 5, but the answer after class is - 1 or 5. What's the matter?
- 18. How to calculate the mixed product of vectors? Given a parallelepiped with three ABC vectors as edges, how to calculate its volume? If we know that V parallelepiped = ABC three vector products, we can't calculate determinant
- 19. What is the original function of the root sign SiNx
- 20. Does (E ∧ x) * ((SiNx) ∧ 2) have an original function? If so, what is it?