First, solve the equation.
5X- 12x 3 = 2 X+ 12 24X = 3 7X+2X = 36 x2
5x-3x 5 = 10 6X-2X-8 = 8xx(3+6)= 18
8 X =6x 12 36 -8 X = 4 X 2x(X-6)= 8
Second, according to the following conditions, talk about the equal relationship between quantity and quantity.
1, 360 poplar and fir trees.
2. White rabbits are 28 less than gray rabbits.
Car a travels 45 kilometers more than car B.
Buying a car is 80 thousand more expensive than buying a van.
Fill in the blanks with the letters in brackets.
(1) Xiaolan has X cocks, and the number of hens is four times that of cocks. There are () hens.
(2) The price of storybooks is X yuan, and the price of dictionaries is 2.5 times that of storybooks. How much is a dictionary, three story books and two dictionaries?
(3) There are X apple trees in the orchard, 12 pear trees are 0.5 times more than apple trees, and there is one pear tree.
(4) There are X teachers in the school, and the number of students is 20 times that of teachers, with 20x representing and 20x+x representing.
Fourth, solve application problems with equations.
1. Miss Wang bought 12 pens in the store, paid 100 yuan and took them back to 22 yuan. How much is each pen?
2. There are 86 badminton in the gym, which is less than four times the number of keys in 14. How many keys are there?
3. The fruit shop needs 2820 Jin of fruit, and has already entered 24 baskets, each with 42.5 Jin and the remaining 60 Jin. How many baskets should we bring in?
4. The original 2,650 kg of flour in the grain store was sold out of 100 bags, and there was still 150 kg left. How many kilograms does each bag of flour weigh?
Problems of Olympiad Mathematics in the Construction of Fifth-grade Mathematical Hutong
The pavement repair plan of an alley with a length of1200m shall be jointly completed by Party A and Party B.. If Party A and Party B work together for 24 days, if Party A and Party B work together for 16 days, Party B works alone for 20 days. How many meters will Party A and Party B build roads every day? If 70 yuan is used every day and Party B uses 40 yuan every day, the project cost will not exceed 2,500 yuan. Q: How many days does the team work at most?