Let's talk about equal relations first.

If the price of trousers is X yuan, then the price of coat is 1.4x yuan.

x+ 1.4x=240

x= 100

Pant price 100 Yuan, coat price1.4x =1.4x100 =140 yuan.

2

If the naughty one has X yuan, the elder sister has 4x yuan.

x+4x=280

x=56

Naughty and rich 56 yuan, my sister is rich 4x = 4x = 4x=4×56=224 yuan.

three

There are x bags of brown sugar, according to the meaning of the question:

2x+5=55

x=25

There are 25 bags of brown sugar.

four

Suppose there are x Chinese books, then there are 2x math books. According to the meaning of the question:

2x+x=24

x=8

There are 8 Chinese books and 2x=2×8= 16 math books.

five

Suppose the mass of apricots is x kg and the mass of apples is 4x kg:

( 1)

x+4x=40

x=8

The mass of apricot is 8kg, and that of apple is 4x = 4x8 = 32kg.

(2)

4x-x=24

x=8

The mass of apricot is 8kg, and that of apple is 4x = 4x8 = 32kg.

six

If there are x green vegetables, there are 3x Chinese cabbages.

3x-x= 150

x=75

75 green vegetables and 3x = 3x = 3x=3×75=225 Chinese cabbages.

seven

If the fourth grade donates X yuan and the fifth grade donates 160+x yuan, according to the meaning of the question:

x+ 160+x=880

x=360

Level 4 360 yuan, level 5160+x =160+360 = 520 yuan.

eight

If naughty, donate X yuan, smile and donate 150+x yuan, according to the meaning of the question:

x+ 150+x=600

x=225

Naughty donation is 225 yuan, and Xiaoxiao donation150+x =150+225 = 375 yuan.

nine

Set up a music group of X people, according to the meaning of the question:

2x-6=34

x= 15

Music group 15 people.

10

Assuming that the WHO recommended sodium intake is x grams, according to the meaning of the question:

2x- 1= 1 1

x=6

The WHO recommended sodium intake is 6 grams.

1 1

Suppose there are x students in grade four, according to the meaning of the question:

5x+20= 1205

x=237

There are 237 fourth-grade students.

12

Suppose the chicken and the rabbit are both x, according to the meaning of the question:

2x+4x = 90°

x= 15

Both chickens and rabbits are 15.

13

Suppose 5 yuan and 10 yuan are both X. According to the meaning of the question:

5x+ 10x= 105

x=7

5 yuan and 10 yuan are both seven.

14

Suppose the chicken and the rabbit are both x, according to the meaning of the question:

4x-2x=28

x= 14

Both chickens and rabbits are 14.

15

We set the fruit juice at X yuan per cup. According to the meaning of the question:

(3+4)x=35

x=7

Juice per cup of 7 yuan.

16

Suppose my age is X, then my mother's age is x+20.

2x=x+20

x= 10

My age is10;

The mother's age is x+20= 10+20=30 years old.

17

Assuming an average of x eggs per bag, according to the meaning of the question:

3x+2=56

x= 18

Average per bag 18 eggs.