A primary school math problem, the process is written clearly

Let A be x, B be y, and C be z, that is, there is a relation:

1 2/5x=1/3y

2 3/4y=7/8z

3 z-x=10

Substituting relation 3 into relation 1 yields relation:

4 y=6/5z-12

Then substituting relation 4 into relation 2 yields:

z=360 i.e. has:

x=z-10=360-10=350

y=（7/8*360）4/3=420

Therefore, A, B, and C spend a total of as follows:

x+y+z=350+420+360=1130 yuan.

Solution: Let A spend x yuan, then 2 5x = 1 3 B, that is, B = 6 5x, 7 8 C = (6 5 * 3 4) x, that is, 7 8 C = 9 10x, that is, C = 36 35x.

From the meaning of the question, 36 35x=x+10, and the solution is x=350.

B = 6 5x, C = 36 35x, x + 6 5x + 36 35x = 113 35x = 113 35 * 350 = 1130 (yuan).

A: A, B and C spent a total of 1,130 yuan.

Well, at least give one

Solution: A 420 1 3 2 5

350 yuan. B 10 (3 4 7 8-1 3 2 5) 420 yuan. C 420 3 4 7 8

360 yuan Total: 420 + 350 + 360 = 1130 yuan Answer: A, B, and C spent a total of 1130 yuan.

The ratio of the amount of money spent by A, B and C is (1 3) (2 5): 1: (3 4) (7 8) = 5 6:1:6 7 = 35:42:36

Therefore, the three people spent a total of 10 * (35 + 42 + 36) (36-35) = 1130 (yuan).

Suppose A's 2 5 is 1

B's 1 3 is 1

Then A is 5 2, and B is 3

A: B = 5 2:3 = 5:6

The same thinking, the same method, B: C = 4 3:8 7 = 7:6 B appears twice in the middle.

Then, unify B.

Then, the ratio between A, B and C is: 35:42:36 C costs 10 yuan more than A, then it costs an extra one.

That one is 10 yuan.

Add up their scores: 35 + 42 + 36 = 113 (parts) and then use 113 * 10 = 1130 (yuan).

Novices, may be a little ambiguous, take your time to understand it, learn together, and make progress together. Look

Let A, B, and C spend money on x, y, and z, respectively

x2/5=y1/3

y3/4=z7/8

x+10=z

Solve the system of equations, get.

x=350y=420

z=360x+y+z=1130

A: A, B, and C spent a total of 1,130 yuan.

A spends x, then B spends x2 5*3=6 5x, and C spends 6 5*3 4*8 7=36 35x

C costs 10 yuan more than A36 35x-x=10

x=350 A flower 350, B flower 420 yuan, C flower 360 yuan, a total of 1130 yuan.

A: B = 1 3:2 5 = 5: 6 = 35:42 B: C = 7 8:3 4 = 7: 6 = 42:36 So A: B: C = 35:42:36

Total flower: 10 (36-35)*(35+42+36)=1130 yuan.

2 5 A = 1 3 B.

3 4 B = 7 8 C.

C-A = 10

A = 350 B = 420 C = 360

In the end, it adds up to 1130 yuan.

Let the money spent by A be x, the money spent by B be y, and the money spent by C be z.

Then the equation can be listed according to the above:

2 5x=1 3y is: 6x=5y then y=6 5x3 4y=7 8z is: 6y=7z

z-x=10 is: z=x+10

Bring z=x+10 into 6y=7z to get :

6y=7x+70

Then bring y=6 5x into the yield:

6（6/5x）=7x+70

Multiply 5 on both sides to get:

36x=35x+350

x=350 brings x=350 into y=6 5x to obtain:

y=420 brings x=350 into z=x+10 to obtain:

Z=360 then: x+y+z=350+420+360=1130, that is, A, B, and C spent a total of 1130 yuan.

Thank you, please give the best.

Let A, B, and C spend x, y, and z yuan respectively.

2 5x=1 3y, i.e. x=5, 6y

3 4y = 7 8z i.e. z = 6 7y

z-x=6 7y-5 6y=1 42y=10 The solution gives y=420, so x=350, z=360

x=y=z=420+350+360=1130 yuan.

Just set 3 unknowns.

2 5 A = 1 3 B.

3 4 B = 7 8 C.

C-A = 10

So you can figure it out.

The answer is A = 350 B = 420 C = 360

2 5 A = 1 3 B.

3 4 B = 7 8 C.

C-A = 10

After simplification, it is available.

A = 350 B = 420

C = 360 A + B + C = 1130

There are x days of sunny weather.

There are 112 in total 14 = 8 days.

It was shipped 20x times on sunny days and 12 (8-x) times on rainy days.

20x+12（8-x）=112

x=2 So there are two days that are sunny and 6 days that are rainy.

Solution: Let's say there are x days of rain in these days.

12x+(112/14-x)×20=112x=6112/14-x=8-6=2

A: There are 6 rainy days and 2 sunny days in a few days.

Solution: You can get a total of 112 14 = 8 (days), so you can have x days that are sunny, then there are (8-x) days, which are rainy days.

The column equation is as follows: 20x+12(8-x)=112 solves the equation to get x=2

So, there are 2 sunny days and 6 rainy days.

Solution: Let sunny days have days and rainy days have (8 x) days (if the sunny days are x, then the rainy days are 8 times less than the sunny days, so (8-x) days).

20 12 (8 x) = 112 (sunny + rainy = all transported).

20 96 12x=112 (multiply 12 by aggressive).

20 12x=112 96 (shift).

8x=16 (I don't need to talk about it later, right?) ）

x=16x8

x=28‐x=8‐2

8 x=6x=2 (days) (Since it's an elementary school topic, you need some units, right?) ）

Answer: Two of the eight days were rainy.

You're supposed to be learning to solve equations, right?

In total: 112 14 = 8 (days).

Solution: There are sunny days and (8) rainy days.

Answer: Two of the eight days were rainy.

Here, '' stands for division.

112 14 = 8 days.

Solution: There are x days of rain.

20x+12(8-x)=112

20x+96-12x=112

8x=112-96

8x=16x=2, so there are two days that are rainy.

Eight of these days were rainy.

112 divided by 14 = 8 (days) 20x +12x = 112 for 5 sunny days and 1 rainy day.

Question 1:

If the number of students in the sixth grade is x, then the number of students in the fifth grade is 2 3x, and the number of students in the fourth grade is y, then:

x+2/3x+y=720

x-y=80

Solution: 5 3x+y=720, y=720-5 3x, so: x-(720-5 3x)=80, x=300, y=220, so: 300 in 6th grade, 220 in 5th grade, and 200 in 4th grade.

Question 2: Set a bag of flour as x kilograms, because the ratio of what you eat on the first day to what you have left is 1:4, then what you eat on the first day is: 1 5x, a bag of flour is divided into five parts, eat one point on the first day, and leave four parts, so it is 1: (5-1), so: 1 5x+40=3 5x, solution: x=100, answer: this bag of flour is 100 kilograms, and 20 kilograms were eaten on the first day.

Question 3: If there are x parts in this batch, then 1 5x is processed on the first day, and 70 are processed on the second day, at this time, the processed ones are: 1 5x+70, and the unprocessed ones are: x-(1 5x+70)=4 5x-70, and the comparison between the two is 3:5, then: (1 5x+70) (4 5x-70)=3 5

Solution: (1 5x+70)*5=(4 5x-70)*3,x+350=12 5x-210,7 5x=560,x=400, A: There are 400 parts in this batch.

Question 4: If the book has x pages, then 1 5x is read on the first day, and (1 5x+6) is read on the second day, and the number of pages left is: x-(1 5x+1 5x+6)=3 5x-6, and the total number of pages read in two days: 1 5x+1 5x+6=2 5x+6, and the comparison between the two is 5:

6, then: (2 5x+6) (3 5x-6)=5 6, solution: (3 5x-6)*5=(2 5x+6)*6,3x-30=12 5x+36,3 5x=66

x = 110, A: The book has 110 pages.

1. If the number of sixth graders is 3x, then the number of fifth graders is 2x, and the number of fourth graders is 3x-80, and the equation is 3x+2x+3x-80=720, and the solution is: x=100, so the number of sixth graders is 300, the number of fifth graders is 200, and the number of fourth graders is 220.

2. From the title, I ate one-fifth of the bag of flour on the first day, and two-fifths of the bag of flour on the second day, so 40 divided by two-fifths is equal to 100, which is the weight of the bag of flour. Ate 20 kg on the first day.

3. The ratio of processed to unprocessed at this time is 3:5 to process three-eighths in the first two days, so the next day is processed seven-tenths (three-eighths minus one-fifth), and this batch of parts is 70 divided by seven-tenths to get 400.

4. The ratio of the number of pages read by the title to the number of pages left is 5:6 to read five-elevens in the first two days, and the next day is five-elevens minus one-fifth of the first day to get fourteen fifths of fifty-five, so the second day is three-fifths more than the first day, so the number of pages in this book is: 6 divided by three-fifths of fifty-fifths to get 110 pages.

1. (x²－2xy＋y²＋3）（－x²＋2xy－y²＋3）＝[3+(x²－2xy＋y²)]3-(x²－2xy＋y²)]

Because (x 2xy y 3) ( x 2xy y 3) (3 a) (3 a).

So a=x 2xy y

2.（2s＋9m）＋[6n－2t）]=2（s+t）+3(3m-2n)

Because s t 21, 3m 2n 9, so the original formula = 2x21 + 3x9 = 69

3.(2x ax y b) (2bx Chashan 3x 5y 1)=(2-2b)x +(3+a)x+b-6y+1

Because it has nothing to do with the value of the letter x.

So 2-2b=0 3+a=0

So b=1 a=-3

Then bring in 3 (a ab b ) 4a only defeat ab b ) to count... I didn't finish my own homework. Defeated.

Now the most important thing you need to do is to relax your mind, and I have a good way to relax your mind is to set your goals for each subject too high. So there won't be too much psychological pressure, and then take a subject and put down a subject, don't think about it, I'm used to listening to ** before the exam, the art department of our school is a student 528 like, the final focus of mathematics should be on the multiple choice questions and the first two big questions If you only require a pass, multiple choice questions are made every day or two, Zheng Bei has to shout Sun Rui if the topic is difficult, I think politics can be a good strengthening between the empty Kai brothers, mathematics is not a day or two to learn well, before the college entrance examination I have a little more than 70 in politics, The college entrance examination is more than 90 points, and the last few days of liberal arts subjects are the best opportunity to add points, don't give up easily, return to the lecture book, write down the key points, where are you a candidate!

The first dust orange: If you look at the other than 3 as a whole, you will know that the square of a=(clear vertical x-y) is big.

Second, first simplify the original formula to 2(s+t)+3(3m-2n)=2*21+3*9=69

Third: the value has nothing to do with x, that is, 2-2b=0, a-3=0, then b=1, a=3 can be calculated by simplifying and substituting it.