Several seventh grade math problems, with a calculator solution 1) The cube root of 28 2) 345 3) Cube root of - 17.6 4) The cube root of 1 / 48 (one in 48) Accurate to 0.1

RELATED INFORMATIONS

• 1. A few seventh grade math problems, solving, urgent! 1. Party A and Party B set out from place a to place B at the speed of 4km per hour at the same time. After 2.5 hours, Party A returned to place a to get the documents. He rushed back to place a at the speed of 6km per hour. After getting the documents, he went back to catch up with Party B at the same speed. As a result, Party A and Party B arrived at the same time, The speed of the ship in still water is 10km / h, and the speed of the current is 2km / h. how many kilometers must the ship go to return to the original Wharf in 8 hours
• 2. There are 8% salt water and 5% salt water in the laboratory. Now we need to mix these two kinds of salt water to make 3kg salt water with 6% salt. How many grams of these two kinds of salt water are suitable?
• 3. Given the equation system x + y = 7ax + 2Y = C, try to determine the value of a and C, so that the equation system: (1) has one solution; (2) has innumerable solutions; (3) has no solution
• 4. 1. The square of the polynomial X of x.y-mxy + 2xy-y to the 2N-1 power + 1 is a cubic trinomial, and the value of the square of (M + n) can be obtained 2. Xiao Ming is doing a math problem: "two polynomials A and B, where b = the square of 3A - 5a-7. Try to find a + 2B." he mistakenly regards a + 2b as a-2b. The answer is the square of - 2A + 3A + 6. Can you help him to calculate the correct result of a + 2B?
• 5. Four mathematical problems No.1 road repair team plans to build a road 150 meters a day and complete it in 12 days. If it is to be completed two days in advance, how many meters should be built every day? No.2 two trains leave from two places at the same time and run in opposite directions. After 4.5 hours, the two trains meet at a distance of 9 km from the destination. The express train runs 42 km per hour. How many kilometers are there between the two places? 2 times, how many students are there in each grade? No.4 a hospital plans to use white cloth with a length of 30 meters and a width of 1.8 meters to make triangular towel for rescue with two right angles of 0.6 meters. How many can be made?
• 6. I'll hand it in tomorrow! There are 1500 bags of rice in a warehouse and 3 / 5 of them are taken away. How many bags have been taken away? How many bags are left? A barrel of oil is 10 kg, 4 / 5 of which is used. How many kg are left? Zhang Jia village has 720 pigs, and the number of sheep is 1 / 8 less than that of pigs. How many sheep did Zhang Jia village have? Zhang Jun weighs 42 kg. Li Ming weighs one seventh of Zhang Jun's weight, and Wang Hai weighs one sixth of Zhang Jun's weight. What are the weights of Li Ming and Wang Hai? Bad, I'll hand it in tomorrow!
• 7. The length of the rectangle is 2xcm, the width is 4cm, the length of the trapezoid is xcm, the length of the bottom is 3 times of the length of the top, and the height is 5cm? How much bigger?
• 8. Two rectangular pieces of paper with equal width are stacked together to get the quadrilateral ABCD as shown in the figure. (1) prove that quadrilateral ABCD is diamond; (2) if two rectangular pieces of paper are 8 in length and 2 in width, does the perimeter of diamond ABCD have a maximum or minimum? If it does, ask for it; if it does not, give a brief reason
• 9. 1. There are 26 bricks, two brothers fight to choose, brother gun in front, just put bricks, brother came. Brother see brother choose too much, bring half to himself. Brother refused, and from the brother to take half. Brother refused, brother had to give brother 5, so brother than brother move 2 more, I ask: at first, how many will brother move? 2. A basket of apples, the first day to eat half more than one, the next day to eat the remaining half less than one, then there are still three. How many apples in this basket? 3. Write three scores (), (), () smaller than 3 / 4 and larger than 5 / 8 4. For a fraction, the sum of numerator and denominator is 20. If the denominator is subtracted by 8, the fraction is equal to 1. The fraction turns out to be ()
• 10. 1. The purchase price of a batch of goods is a yuan. If the gross profit (what is it?) is to account for 30% of the bid price, the bid price should be a yuan? 2. The length of one right side of a right triangle is reduced by 25%. To keep its area unchanged, the other side should be increased () A. A quarter B. a quarter of it c. a third of it D. two fifths of it
• 11. Solving a math problem in the second semester of grade seven If the inequality system A-X > 0, x + 1 > 0 has no solution, the value range of a needs to be solved
• 12. What is the zero power of (- 2) + (negative half) / (negative second power of negative half) * (negative third power of negative half)
• 13. 1. Party A and Party B ride bicycles from two places 65km apart at the same time. After two hours, Party A and Party B meet. Party A rides 2.5km more per hour than Party B. find out the speed of Party B 2. A passenger's train is moving at a speed of 40km / h. he sees the oncoming train passing by him in 3S. It is known that the oncoming train is 75m long. Find the speed of the oncoming train. (train equation solution) 3. A and B practice the 100m race. A runs 7m per second and B runs 6.5m per second. If a asks B to run for 1s first, a can catch up with B in a few seconds 4. Both Party A and Party B go from place a to place B. Party A walks 5km per hour, 1.5h first; Party B rides a bicycle, and Party B walks for 50min. They arrive at the destination at the same time, and ask Party B how many kilometers per hour 5. The distance between the enemy and us is 28km. We know that the enemy fled at the speed of 8km per hour one hour ago. Now our army is chasing the enemy at the speed of 14km per hour, and can catch up with the enemy in a few hours
• 14. The third power of 2 + the third power of 4 + the third power of 6 + the third power of 8 + +The third power of 100 =?
• 15. (-1)+3+(-5)+7+(-9)+11…… +(-2007)+2009 (1/1X3)+(1/2X5)+.+(1/2003X2005) (1/1X4)+(1/4X7)+(1/7X10)+.(1/2002)X(1/2005)
• 16. The product of four integers a.b.c.d that don't want to be equal ABCD = 9, find a + B + C + D Mr. Wang sold two kinds of stocks at the same time. A made a profit of 20% when selling 1200 shares. B also made a loss of 20% when selling 1200 shares. Is the total profit or loss? When a plane flies between two cities, the wind speed is 244m / h. It takes 5 hours for downwind and 6 hours for headwind to find the distance between two cities There are two water inlet pipes in the pool, which are filled in 3 hours after opening a, 2 hours after opening b, and how many hours after opening both pipes? AB two runs, a lap 3 minutes, B lap 2 minutes at the same time running in the opposite direction, the first meeting in a few minutes?
• 17. A, B, C three water pipes, open a pipe alone 5 hours to fill the pool; a and B two pipes open together, 2 hours to fill the pool; a and C two pipes open together, 3 hours to fill the pool. Now open a, B, C three pipes together, after a period of time a pipe failure to stop water injection, but 2 hours later the pool full, ask a, B, C three pipes together put how much time Water?
• 18. Wang Qiang took part in a 3000 meter race. He ran a part of the distance at the speed of 6 meters per second and finished the rest at the speed of 4 meters per second. It took 10 minutes. How many meters did Wang Qiang run at the speed of 6 meters per second?
• 19. The distance between a and B is 22.5km, and they are facing each other at the speed of 2.5km and 5km per hour respectively. Meanwhile, the dog with a runs to B at the speed of 7.5km per hour. The dog runs back to a immediately after meeting B, and then runs to B again after meeting a Until a, B meet, then the dog's journey is______ ．
• 20. Some of the same rooms need wall painting. Three first-class technicians go to paint eight rooms a day. As a result, there are 50 square meters of future wall painting and painting. In the same time, five second-class technicians paint another 40 square meters of wall besides 10 rooms. Each first-class technician paints more than 10 square meters of wall in one day than the second-class technician, so the wall area of each room needs painting There are a group of pigeons and some pigeon cages. If 6 pigeons live in each pigeon cage, the remaining 3 pigeons have no pigeon cages to live in. If another 5 pigeons fly together with the original pigeons, each pigeon cage just lives in 8 pigeons. How many pigeons and pigeon cages are there?