![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
（2X-Y）²-4（X-Y）*（X+Y）-（X-Y）*（X-1）
（2X-Y）²-4（X-Y）*（X+Y）-（X-Y）*（X-1）
=4x²-4xy+y²-4x²+4y²-x²+xy-y+x
=-x²-4xy+5y²+xy-y+x
RELATED INFORMATIONS
- 1. Given that the area of a circle is 78.5cm, the circumference of the circle is
- 2. Xiaodong has a bicycle with a diameter of about 66cm. If the average speed is 100 cycles per minute, the distance from home to school is 2000m. How many minutes does it take?
- 3. The side length of a square lawn is increased by 2 meters, and the area is increased by 40
- 4. 1. On an east-west freeway, there are two cars a and B driving westward. The speed of car a is faster than that of car B, and there is a certain interval between them___ As a reference, car a moves westward and car B moves eastward_____ As a reference, both AB and ab move eastward 2. An object moves in a straight line for 6 seconds. The average velocity in the first 2 seconds is 6 m / s, and the average velocity in the last 4 seconds is 3 M / s 3. The distance between Party A and Party B is 162km. The car starts from place a at the speed of 10m / s. after driving 72km, it drives to place B at the speed of 45km / h. The average speed of the car from place a to place B is calculated 2.3 write the process: known; seek; solve; answer
- 5. The distance between the two feet of the compass is set at 3cm. What are the circumference and area of the circle drawn?
- 6. Find the minimum positive period of function f (x) = 2 (sin2x) ^ 2 + 4sin2x * cos2x + 3 (cos2x) ^ 2, and find the minimum and maximum
- 7. Divide a circle into 16 equal parts to form a short-sighted rectangle. The circumference of the rectangle is 41.4, and its area is
- 8. If a set of data x1, X2, x3.xn is known, the average is a, the variance is B, and the standard deviation is C If we know that the average of a set of data X &;, X &;, X &;. Xn is a, the variance is B, and the standard deviation is C, then the average of another set of data 3x &; - 2,3x &; - 2,3x &; - 2,. 3xn-2 is variance, and the standard deviation is C
- 9. If the perimeter of a large square is 20cm longer than that of a small square, the difference in area is 35cm2 What is the length of each side of the two squares?
- 10. Parameter estimation problem: let the population obey the uniform distribution of θ - 1 / 2 to θ + 1 / 2, x1, X2 Xn is the sample from the population, and the sample mean is x average Let the population obey the uniform distribution from θ - 1 / 2 to θ + 1 / 2, x1, X2 Xn is the sample from the population. The mean value of sample X and (x (1) + X (n)) / 2 are unbiased estimates of θ. Which is more effective? The key is how to find the variance of (x (1) + X (n)) / 2. X (1) represents the minimum value of n samples, and X (n) represents the maximum value of n samples
- 11. In the parallelogram ABCD, E.F AB.AD And BF = De, BF and de intersect at point P, the bisector angle c of CP is proved
- 12. It is known that, as shown in the figure, a is a point on EF, and the quadrilateral ABCD is a parallelogram with ∠ ead = ∠ BAF. (1) prove that △ CEF is an isosceles triangle. (2) which two sides of △ CEF are equal to the perimeter of the parallelogram ABCD? Prove your conclusion
- 13. As shown in the figure, divide the diagonal AC of the square ABCD into 6 segments, and make a square with each segment as the diagonal. Let the sum of the circumference of the six small squares be p, square ABCD What is the relationship between P and l?
- 14. The starting price of a taxi in a city is 5 yuan (within 3 km), and the average price is 1.5 meters per kilometer for more than 3 km. Xiaomin's family pays 8.9 yuan for the distance between them when they go to grandma
- 15. As shown in the figure, if there is a point E in the square ABCD and the triangle EBC is an equilateral triangle, what is the degree of ∠ bea?
- 16. Given the position of a, B and C on the number axis as shown in the figure, try to simplify: | A-B | + | B-C | + | c-a| As shown in the figure: ———|————————|————|————————|—→ c 0 a b
- 17. If the positions of numbers a and B on the number axis are shown in the figure, then | B | - | a | = -? - a -------- - 0 -------- B is simplified
- 18. 15. The position of a, B and C on the number axis is shown in the figure, which is simplified |a|+|b|+|c|-|a+b|+|b-1|-|c-a| ____ C_______ b_____ 0__ 1_____ a
- 19. The position of the number a and B on the number axis is shown in the figure to simplify | a + B | + | B-A | + | B | - | a - |||
- 20. Given the position of a, B and C on the number axis, as shown in the figure, simplify | a | a + | B | B + | C | C