1. Calculation: X-Y of X + y + Y-3 of 2x 2. Calculation: x + 3 of X & # 178; - X-2 divided by (2-x) + X + 3 of X + 1 | Math enthusiast | Mathematical art

1. Calculation: X-Y of X + y + Y-3 of 2x 2. Calculation: x + 3 of X & # 178; - X-2 divided by (2-x) + X + 3 of X + 1

1. Calculation: X-Y of X + y + Y-3 of 2x = (x + y) / (X-Y) + 2x / (Y-3) = ((x + y) (Y-3) + 2x (X-Y)) / (X-Y) (Y-3) = (xy-3x + y ^ 2-3y + 2x ^ 2-2xy) / (X-Y) (Y-3) = (- 3x + y ^ 2-3y + 2x ^ 2-xy) / (X-Y) (Y-3) = (- 3x-3y + y ^ 2-xy + 2x ^ 2) / (X-Y) (Y-3) 2

RELATED INFORMATIONS

1. 15 / 2 by 10 / 3 17 / 8 by 4 / 1 25 / 9 by 12 / 5 10 / 6 by 15 / 7 9 / 8 by 4 / 27 7 / 5 by 25 / 11 3 / 2 by 5 / 6 If it's right, I'll offer a reward. If it's wrong, I won't offer a reward 2 of 15 times 3 of 10, 8 of 17 times 1 of 4, 25 / 9 times 12 / 5, 10 / 6 times 15 / 7, 9 / 8 times 4 / 27, 7 / 5 times 25 / 11, 3 / 2 times 5 / 6
2. Four x minus three fifths equals five
3. 1,4,9,16,25?64,81
4. 1 divided by 35 percent equals =? 1 divided by 0.375 equals? Out of form calculation
5. One plus eight plus 58 times 108
6. (48 of 48 + 49) divided by 24
7. Mathematical Olympiad of primary school At 21:00 p.m. on March 19, 2012, the national development and Reform Commission issued the second fuel price increase in the year: it decided to increase the prices of gasoline and diesel by 600 yuan per ton from 0:00 p.m. on March 20, and the maximum supply prices of gasoline and diesel standard products for transportation, civil aviation and other special users after adjustment were 9580 yuan per ton and 8730 yuan per ton respectively. Sichuan Provincial Price Bureau decided to adjust the market oil price according to the national requirements from 0:00 p.m. on March 20 (1) A certain type of gasoline in Chengdu market is about 1277 liters per ton. The original price is 7.55 yuan per liter (2) When Mr. Zhang arrived at the gas station at 22:00, he found that there was only one gas dispenser open at the gas station, and there was a long queue of cars waiting for gas, and there were cars coming up behind him. In the process of waiting for refueling, Mr. Zhang found that it takes 3 minutes for each car to refuel on average, and the number of cars queuing behind increased by 2 every 3 minutes. When Mr. Zhang finished filling up, it was 23:12. At this time, the gas station decided to fill up all the waiting cars before adjusting the price of gasoline, so that the cars arriving at the station could fill up the gas without waiting. How many more gas dispensers should the gas station open at least?
8. 1+2+3+4+5+6+7+8+9.+81+82+83+84+85+86+87+88+89+90.
9. How to calculate 55 * 0.98
10. cos25°sin70°-sin20°cos65°
11. In 2005, the number of days with excellent air quality accounted for 5 / 3 of the whole year?
12. How many days are there from June 24, 2011 to June 24, 2012?
13. 5. P is the point on the right branch of hyperbola x ^ 2 / 9-y ^ 2 / 16 = 1, m and N are the points on the circle and circle respectively, and the maximum value of pn-pm can be obtained
14. (2011 · Anhui simulation) if the point P (1,1) is the midpoint of the chord Mn with circle (x-3) 2 + y2 = 9, then the linear equation of the chord Mn is () A. 2x+y-3=0B. x-2y+1=0C. x+2y-3=0D. 2x-y-1=0
15. It is known that the parameter equation of the straight line is x = 1 + 2T, y = 2 + t Given the linear parameter equation {x = 1 + 2T, y = 2 + T (t is the parameter)}, then the chord length of the line cut by the circle x ^ 2 + y ^ 2 = 9 is In my teaching assistant answer, I changed this formula into x = 1 + 2 / root 5T and y = 2 + 1 / root 5T. How does this change
16. It is known that the equation of a circle is (x-1) 2 + y2 = 9, and the tangent equation of a circle passing through a point (- 2,4) is obtained
17. If there is only one common point between the straight line passing through point (1, - 3) and hyperbola x ^ 2-y ^ 2 = 4, find the slope k of the straight line The answer is 1 or - 1 or 1 + 4 √ 3 / 3 or 1-4 √ 3 / 3
18. As shown in the figure, D is the midpoint of the AC side in the equilateral triangle ABC, e is on the extension line of BC, de = dB, if the perimeter of △ ABC is 6, then the perimeter of △ BDE
19. If the points P and Q are on the line AB, and AP: Pb = 2:3, AQ: QB = 3:4, and PQ = 4, find the length of ab Map to process (no map is OK) a variety of solutions to complete~
20. How to use the lever principle of tweezers? How to draw the schematic diagram of its power and resistance? Also, which direction is the schematic diagram of the power of pulling nails with a hammer? So does the direction of power and resistance not have to be opposite or opposite?