Big brother and sister, I won t use assumptions or substitutions for math problems to have equations

1. Set a bag of flour weighs x kg, so a bag of rice has 2x kg, so, 50x+40x=2250, so x=25, 2x=50kg. So a bag of rice 50 kg.

2. If there are x chickens, then there are 29-x rabbits, 2x+4(29-x)=92, so x=10, 29-x=19, so there are 10 chickens and 19 rabbits.

3. If you buy x stamps of 4 points, then you buy 20-x stamps of 8 points, so 4x+8(20-x)=100, so x=15, so you buy 15 stamps of 4 points.

4. Set 5 yuan of tea x kilograms, so 8 yuan a kilogram of tea 10-x kilograms, so 5 x + 8 (10-x) = 71, so x = 3, 10-x = 7, so 5 yuan a kilogram of tea 3 kilograms, 8 yuan a kilogram of tea 7 kilograms.

5. Let the cart be pulled x times, so the trolley is pulled 70-x times, so 7x+4(70-x)=400, so x=40, 70-x=30, so the cart is pulled 40 times, and the trolley is pulled 30 times.

1. If the flour weighs x, the rice weighs 2x, then 20*2x+50x=225090x=2250

x=15, then the rice weighs 2x=30kg

2. Set up x chickens and rabbits.

x+y=29

2x+4y=92

x=12y=17

3. Set 4 points x sheets, 8 points y sheets, then.

x+y=20

4x+8y=100

x=15, y=5 4 points bought 15 sheets.

4. Set 5 yuan to buy x kilograms, 8 yuan to buy y kilograms, then.

x+y=10

5x+8y=71

x=3,y=7

Question 1: Set: A bag of rice weighs xkg.

Solution: 20x+

x=50(kg)

A: A bag of rice weighs 50kg.

Question 2: Set: There are x chickens and y rabbits.

x+y=29

2x+4y=92

Solution: x-12 (pcs).

y=17 (pcs).

A: There are 12 chickens and 17 rabbits.

1. If the weight of 1 bag of rice is x and the weight of a bag of rice is y, then there is.

x=2y20x+50y=2250

The solution of the two formulas is x= y=

There are x chickens and y rabbits in the cage.

x +y =29

2x+4y=92

The solution of the two formulas is x= y=

3. Set x stamps with 4 points, and stamps (20-x) with 8 points.

4x+8（20-x）=100

Solution x=4, set 5 yuan 1 kg of tea x kg, 8 yuan 1 kg of tea y kg.

x+y=10

5x+8y=71

The solution of the two formulas is x= y=

The mass of the orange is three times that of an apple, so the 36 kilograms are divided into 4 parts, and 1 part of the weight is hidden from the apple, and 3 parts are from the orange.

So the apple weight is 36 4 = 9 kg; The weight of the orange is 36 4 * 3 = 27 kg.

Students, in fact, I really miss your state macro question, but if you don't give it to the homework questions, you will give it.

This question is aimed at the question of the book of people who go to elementary school. Sweat!

The first question needs to be replaced: the price of 2 basketballs = the price of 3 volleyballs, then the price of 12 volleyballs and 6 basketballs is the price of 21 volleyballs, then the price of a volleyball is 252 21 = 12 yuan.

In the same way, the price of 12 volleyballs and 6 basketballs is the price of 14 volleyballs, so the price of one volleyball is 252 14 = 18 yuan.

The second question also needs to be replaced: each time the large truck is loaded with 4 tons more than the small truck, then, 36 large trucks are loaded with 36 * 4 = 144 tons more than 36 small trucks, and the 144 tons are loaded by the remaining 9 small trucks. Then, 45 pickup trucks loaded with 144*45 9=720 tons.

1.In the title, it is said that "the price of buying 2 basketballs is equal to the price of buying 3 volleyballs", that is, the price of buying 6 basketballs is equal to the price of buying 9 volleyballs, and then using the replacement method to turn the basketball into a volleyball, so that the volleyball can be solved at 12 yuan each, and then the basketball is 18 yuan each.

2.Assuming that each small truck can be loaded with an unknown number of tons, then, the number of each large truck can be loaded is to add 4 tons on the basis of the number of each small truck, because the same batch of steel is transported, so the results are equal, equal to the total amount of this batch of steel. This results in a total of 16 tonnes of steel.

PS: To be honest, if the second problem is not solved by equations, it is quite difficult, complicated, and annoying.

Question 1: Assuming that the price of 2 basketballs is equal to the price of 3 volleyballs, and the price of 6 basketballs is equal to the price of 9 volleyballs, then it can be seen that a total of 21 volleyballs were bought, and 21 = 12 yuan were used for 252 yuan, then the price of basketballs = 12 * 3 2 = 18 yuan.

Question 2: Assuming that this batch of steel is all loaded with large trucks, 36 are needed, and each large truck is 4 tons more than small trucks, then 36 * 4 tons = 144 tons, which is the number of tons loaded by 36 large trucks than 36 small trucks, and assuming that 45 small trucks are loaded with the same tonnage as 36 large trucks, and 45-36 = 9 small trucks are used to load 144 tons of steel, then 144 9 = 16 is the tonnage of each small truck, and 45 - 16 tons = 720 tons is the number of this batch of steel.

Because the price of buying 2 basketballs is equal to the price of buying 3 volleyballs, a total of 21 volleyballs are bought, 252 21=12,12x12=144,252-144=128,108 6=18

36x4÷9=16.

252 (12+6 2*3) is equal to 12 yuan for a volleyball.

252-12*12) 6 is equal to 18 yuan for a basketball.

6 40 2-40 = 40 40 (bag B) 60 2 = 120 (bag A).

7 15 2-14 = 16 16 (3 + 1) = 4 (what remains after A poured B) 16-4 = 12 (after B doubled).

12 2 = 6 (B sells left) 16-6 = 10 (A sells left) 15-6 = 9 B sells 15-10 = 5 A sells 8 4 bottles of beer, the diameter of the square is 14 cm, and the diameter of the circle outside the square is (7 + 7 times, root number 2) cm.

At least 2) cm of packing rope is required.

10 At the same time, whoever walks more distance, the speed of the water is faster, Xiao Wang walked 1-1 3=2 3=30 45

Xiao Li walked 1-2 5 = 3 5 = 27 45

Xiao Zhang walked 1-4 9=5 9=25 45

Xiao Wang is the fastest, and Xiao Li is second. Xiao Zhang is the slowest.

6. Set the quality of bag B to x

2x+40=

x = 60 bag A mass 120 kg, bag B mass 60 kg.

7. A total of 30 kilograms, 14 kilograms were sold, and the remaining 30-14 = 16 kilograms B barrel is 3 parts of A barrel, A barrel 16 (1 + 3) = 4 kg B barrel 16-4 = 12 kg.

Then there is 12 2 = 6 kg left in the barrel.

B barrel sold for 15-6 = 9 kg.

A bucket sold for 14-9 = 5 kg.

The diameter of the bottle beer that makes up the square is 14 cm.

Beer bottles are 7 cm in diameter.

The packing rope is 7*4+ cm.

Tons = 6000 kg.

1 kg of salt requires 6000 80 = 75 kg of seawater.

80 6000 = kg per kilogram of seawater salt.

10. Four-tenths to two-fifths and more than one-third.

4 9=20 45 2 5=18 45 4/9 is more than 2/5 2 5=15 6 1 3=5 15 2/5 is more than 1/3 so Xiao Zhang has the most remaining distance, Xiao Li is second, and Xiao Wang has the least remaining distance, so Xiao Wang is the fastest.

Analysis: 25 kg taken from each box, 7 boxes taken in total: 25 7 = 175 kg;

The weight of the remaining grapes in 7 boxes is 5 kg more than the weight of the original 3 boxes of grapes" If the total weight of 175 kg taken in 7 boxes is added to "5 kg more", that is: 175 + 5 = 180 kg, then these 180 kg is the total weight of the original (7-3) boxes, so the original weight of each box of grapes: 180 (7-3) = 45 kg. Comprehensive Formula:

6. Solution: Set B bag x kg of rice, then bag A is 2x kg of rice, according to the title:

2x+40=(x+40)×

x = 60 armor bag 2x = 120

7. Solution: Set a barrel to sell x kilograms of oil, and there are (15-x) kilograms of oil left; Then barrel B sold (14-x) kilograms of oil, and there was still [15-(14-x)] that is, (1+x) kilograms of oil, according to the title:

1+x) 2=[15-x-(1+x)] 3x=5B barrel sold: 14-x=9 (kg).

4 + cm) 9, (1) 6000 80 = 75 (kg).

2) 80 6000 kg).

10. Xiao Wang's speed: 2 3 8 15 is equal to 5 4 is equal to Xiao Li's speed: 3 5 8 15 is equal to 9 8 is equal to Xiao Zhang's speed:

5 9 8 15 equals 25 24 Therefore, Xiao Wang's speed is faster.

There are so many questions, and there is no point, so everyone is really cheap labor!!

1.Assuming that one is not damaged, the resulting key mold empty money = (500*6 10)*;

The money that is blind in the present manuscript =,The number of yards that are broken by the land = (

2.Assuming that all adults are adults, the number of breads eaten = 99 * 2 = 198;The number of children eaten now = 99, so the number of children = (198-99) (2-1 2) = 66

Number of adults = 99-66 = 33

6 500 = 3000 (yuan).

1. Assuming that all are intact, then the yuan will be more than the actual yuan, this is because there is indeed some damage to the hail, and each damage is less than the yuan, so it is damaged.

Eat per child: 1 2 = pcs).

2. Assuming that 99 people are all adults, then eat bread 2 99 = 198, which is 198-99 = 99 more than the actual one, this is because the children are counted as adults, and each person is counted more, so there are 99 children, and adults have Zhen Mingfan 99-6 = 33 people.

Of course, it can also be assumed that 99 people are all children, then they eat bread, and eat less than Shihuai Boji, this is because adults are counted as children, and each person is counted less, so there are adults, and children have 99-3=66 people.

If the bottom area of container A is 35*20=700, and the bottom area of container B is 20*15=300, if the same amount of water is poured into it, the ratio of the rising height of the water surface of A and B is 3:7, that is, the rising speed of A will be 3 7 of the speed of B.

Originally, the water surface of A was 8 high, and the water surface of B was 5 high, and when they rose to the same height, it means that B was fast enough to make up for the original 3 centimeters, and B was 4 3, 3 4 3 = 9 4=, and B was faster than A, so A rose to and rose; b went up, went up. Then the amount of water poured is 700 * cubic centimeters.

I used the method of elementary school, which is more difficult to understand, if you are in junior high school, you can watch other people's it).

Let the water surface be higher than container A xcm, 20 15 (x+3)=35 20 x, and the solution is x=.

The volume of water is: cubic centimeters.

Let the same amount of water be poured into both containers at the height of h

Then: 35*20(h-8)=15*20(h-5) (8<=h<=18).

7(h-8)=3(h-5)

7h-56=3h-15

4h=41h=41/4

v = 15 * 20 * (41 4-5) = 1575 A: 1575 cubic centimeters of water into each of the two containers.

Let the volume be x cubic centimeters.

x÷（35*20）+8=x÷（20*15）+5x/700+8=x/300+5

3=1/100*x*（1/3-1/7）

x=300÷4/21

x=1575

Please check if there is any mistake?

Picked 120 12 = 10 days.

Assuming that all 10 days are sunny, then 10 20 = 200 pine nuts.

200-120 = 80 more

Rainy days: 80 (20-10)=8 (days).

Sunny days: 10-8=2 (days).

A: 2 of these days were sunny and 8 were rainy.