Two practical questions

1.Solution: If there are x adults and children, then children will have (99-x) people.

2x+（99-x)/2=99

Solution: x=33

99-x=66

A: There are 33 adults and 66 children.

2.(1) There are 52 fewer rabbits than chickens, which refers to the number.

Solution: If there are x chickens, there are rabbits (x-52).

2x+4（x-52)=206

Solution: x=69

x-52=17

A: There are 69 chickens and 17 rabbits.

2) There are 52 fewer rabbits than chickens, which refers to the number of feet.

Solution: There are x chickens and y rabbits.

2x+4y=206

2x-4y=52

Solution: x=y=hee hee The second assumption should be wrong!

1.Let the number of adults be x and the number of children be y. According to the problem, x+y=99 2x+1 2*y=99 is solved to x=33 y=66

2.If there are x chickens, then the rabbits will be x-52. Chicken has 2 legs and rabbit has 4 legs All can be seen from the question: 2x+(x-52)*4=206 The solution is x=69 So the rabbit is 17.

1) X for adults and y for children

x+y=99

2x+y/2=99

x=33y=66

2) Chicken = 134

Rabbit = 72

(1-25%-30%) = 2000 (meters).

2. The concentration becomes larger, add salt, and prepare Huai assuming that x grams of imitation Juyou salt are added.

Answer: x + 200 20%) 200 + x ) = 36% x = 50

Rice. 2.Ying Zhaoqiao should add salt, and destroy the guess to quietly add x grams of fiber slag salt.

200*20%+x）/（200+x）=36%

Question 1:

Suppose the first floor is x room, and according to the conditions, there are 4x<48 and 5x>48, and the joint solution is 7, so x=10. This means that there are 10 rooms on the first floor and 15 rooms on the second floor.

Question 2: There were originally x-2 students, and each student shared 300 (x-2) yuan;

After adding 2 students, each student will share 300 x yuan;

Therefore, the original student shared 300 (x-2)-300 x yuan less, and simplified it to 600 x (x-2) yuan.

4 people per room: 48 4 = 12 rooms, the number of rooms is not enough, indicating that it is less than 12 rooms 5 people per room: 48 5 = 9 ......3, to live in 10 rooms, one is not full, in line with the topic.

Therefore, it can be proposed that the first floor is 10 rooms, if you live on the second floor for 3 people per room: 48 3 = 16 rooms, you need 16 rooms, but the number of rooms is not enough, indicating that the actual number is less than 16.

4 people per room: 48 4 = 12 same, there are vacant rooms, indicating that the actual number is more than 12, and the number is more than 12 than 16.

Because 15-5 = 10

The second floor has 5 more rooms than the first floor, and the first floor can be determined to be 10 rooms based on the above.

If there are x rooms on the first floor of the hotel, then there are x + 5 rooms on the second floor From the title: 48 4> x 48 5x+5 48 4

Question 1: 48-4x>0

48-5x<0

48-3(x+5)>0

48-4(x+5)<0

48 5 so x takes 10

Question 2 Whether there is a lack of conditions The answers are not uniform.

(4+3)=4 7, post-white chalk proportion;

17 (17 + 18) = 17 35, first white chalk ratio 3 (4 7-17 35) = 35 boxes, this box of chalk has a total of 35 boxes: remaining distance = 4: (4-3) = 4:

1. It is 2,000 meters in the fertility bureau, that is, when Xiaogang arrived at B, Xiaoqiang was still 2,000 meters away from B.

At the time of the first count, one was x

17x-3):(18x+3)=4:3 There is no solution to this problem, because there is less white chalk, and if you change 3 boxes of it, there will be less, and it is impossible to become a situation where 4:3 is more than chalk.

2 set Xiaoqiang walked x meters 8000:4=x:3 x=60008000-6000=2000, and 2000 meters.

Analysis: The first question should grasp that no matter how wrong you are, the total number of copies is the same. The first white chalk accounts for 17 (17+18)=17 35 of the total, and the second white chalk accounts for 4 (4+3)=4 7.

Why is it inconsistent, because if you look at 3 boxes of white chalk as colored chalk, that is, the difference in the number of white chalks between the two times is 3, which corresponds to a fraction of (4 7-17 35).

Solution: 3 (4 7-17 35) = 35 boxes.

The second question should seize the time to be certain, the distance is proportional to the speed, 8000 * (1-3 4) = 2000 meters.

3 4 7-17 35 = 3 20 35-17 35 =3 3 35 = 3 35 3 = 35 (box).

A: There are 35 boxes of chalk in this box.

Question 1: 3 (4 7-17 35) = 35 (box).

Question 2: The speed ratio of Xiaogang and Xiaoqiang is 4:3, then the distance ratio is also 4:3 at the same timeSo Xiaoqiang is still far away from B

8000-8000*(3 4)=2000 (meters).

The speed of a cheetah is 110 kilometers per hour.

There are 350 chickens.