Please help me with the math problem 7 in total with columnar formula .

1, There are two kinds of cars in total, and there are three options, which can only be either all A, or all B, or A and B.

Full rental A: The number of vehicles is 27 8=, so you have to rent 4 cars, and the cost is 4 * 300 = 1200 yuan;

Full rental B: then the number of vehicles needed is 27 4=, so you have to rent 7 cars, and the cost is 7 * 200 = 1400 yuan;

A and B are rented: Analyze it, the cost of a person is 300 8, and the cost of B is 200 4, indicating that A is low, that is, A rents 3 cars, and the remaining 3 people can rent a B car. Fee = 3 * 300 + 200 = 1100 yuan.

2. There is such a relationship between them: the number of people in workshop 1 minus one-fifth of it is equal to the number of people in workshop 2 plus one-fifth of workshop 1. That means that workshop 2 is three-fifths of workshop 1, so workshop 1 is 5:3 than workshop 2.

740 = 460 (person).

4. If there are x chickens, then 30-x rabbits.

Then there are: 2x-4(30-x)=80 solution x=20.

1) Section. 1. 1 car of type A, 5 cars of type B 300 * 1 + 200 * 5 = 1300. 2. 2 cars in type A, 3 cars in type B 300 * 2 + 200 * 3 = 1200.

3. 3 cars in category A, 1 car in category B 300 * 3 + 200 * 1 = 1000 (minimum).

2) Set the first workshop for x people and the second for y people.

4/5x=1/5x+y

3/5x=y

x/y=5/3

4) Set up x chickens and rabbits.

x+y=30

2x+4y=80

x=20 y=20

5)6000x(1+

6) The speed of A = 4x24 3 = 32

ab=32x(4+3)=224

7) The circumference of the circle is.

Radius = (Area of a circle = Area of a rectangle.) There is a diagram that the width of the rectangle is 2, and the length of the rectangle is.

The circumference of the shadow = the circumference of the rectangle - 2 times the radius + the circumference of 1 4 circles = look at you, thank you.

Question 1 A1B, the cost is 1100, A3B, 1200 A 1200, so 3A1B has the least cost, at least 1100 yuan.

Question 2: Set the number of people in workshop 1 as x, and the number of people in workshop 2 as y

Columnar formula: 4x out of 5 = y + 1x out of 5

The outstanding result is: x:y=5:3

Question 3: 1200-740=460

Question 4: Set x chickens and y rabbits.

Column two equations x+y=30;2x+4y=80 gives x=20, y=10

Question 5: 6000+ to calculate the result).

Question 6: I'm sorry, but I'm not very good at this question.

Question 7: Let the radius of the element be r

2 r=, solution r=2cm

Multiply by r by the square =

Let the length of the rectangle be x,2x=,x=

So the circumference of the rectangle is.

So the shadow perimeter is.

1) 4 A or 7 B or 3 A and 1B.

The cost of three cars A and one B is at least 1,100 yuan.

2) There were x people in the first workshop and y people in the second workshop.

Then 4x 5 = y+x 5

The solution is x:y=5:3

That is, the number of people in the first workshop: the number of people in the second workshop = 5;3

3) 1200-740 = 460 more people.

4) Set up x chickens and rabbits.

x+y=30

2x+4y=80

The solution is x=20 y=10

That is, there are 20 chickens and 10 rabbits.

5) 6000 (1+RMB.)

6) 4 hours of encounter: Then car B drove a total of 24*4=96km before the meeting, and car A completed this journey in 3 hours.

So the speed of car A is 32km h

So distance = 4 * (32 + 24) = 224km

7) Let the radius of the circle be r and the rectangle of the rectangle a

Circumference = 2 r =

Get r=2cm

Then the area of the rectangle = the area of the circle = r =

So the shadow area = the area of the rectangle - a quarter of the area of the circle =

1) Section. 1. 1 car of type A, 5 cars of type B 300 * 1 + 200 * 5 = 1300. 2. 2 cars in type A, 3 cars in type B 300 * 2 + 200 * 3 = 1200.

3. 3 cars in type A, 1 car in type B, 300 * 3 + 200 * 1 = 1100, so the third type of cost is at least 1100 yuan.

2) (1-1 5)*x=(1 5)*x+y x:y=5:33)1200-740=360 people.

4) Set up x chickens and rabbits.

x+y=30

2x+4y=80 x=20,y=10

1. Decimeters.

Specifically, it can be seen that there are two semicircles on both sides, two diameters of 2, one day and one night in the middle, and the hour hand has gone two times.

2* square centimeters.

The area covered by the hour hand is 5652 square centimeters.

3. Square paper with a circumference of 4 cm, side length = 4 4 = 1cm1 * square centimeter.

The area of the remaining part is a square centimeter.

Decimeter 2Walking twice in a day and night, area = 2 * pi * 30 2 = 5652

3。The circumference of 4 sides is 1, and the remaining area = 1-pi*

1.The length of the tape used is the perimeter of the bamboo cross-section l=dm2The hour hand turns two weeks in a day, which is the area of two circles. s = square centimeter 3The side length of the square is 1, the maximum radius of the circumscribed circle is centimeters, and the area is s = square centimeters, where is the pie.

Ducks = 135 (4-1) 1 = 45 ducks.

Chickens = 45 4 = 180 chickens.

Pears = 128 (8+1) 1 14 boxes.

Apples = 128-14 = about 114 cases.

Solution: Let the divisor be x and the dividend be (8x+1).

x+(8x+1)+8+1=118

x+8x+1+8+1=118

x+8x=118-1-8-1

9x=108

x=12 dividend = 8x + 1 = 8 12 + 1 = 97 Answer: The divisor is 12 and the dividend is 97.

570-370) (5-3) = 100 RMB.

According to the title, the number of A is 10 times that of B.

B number = 253 (10+1) 1 = 23

A number = 253-23 = 230

15 8 (8-2) = 20 kg.

Longan tree = 480 (3+1) 1 = 120 trees.

Mango trees = 480-120 = 360.

Solution: Let the correct product be x.

x÷21=（x-1107）÷12

21（x-1107）=12x

21x-23247=12x

21x-12x=23247

9x=23247

x=2583

Answer: The correct product is 2583.

1.Let the duck be x and the chicken be 4x

4x-x=135

x=454x=180

Apple: pear=8;1

The following can be solved with equations, it's not very difficult, think for yourself, I'm very busy right now.

100,000 * 17% = 10,000 7

480*5%=24 yuan.

427 7% = 6100 yuan.

3500-1600) * 5% = 1900 * 5% = 95 yuan (1) Xiao Wang's manuscript fee is 1000 yuan, and the tax payable is (1000-800) * 14% = 28 yuan (2) Xiao Li pays 280 yuan in taxes, then the manuscript fee is 280 14% + 800 = 2800 yuan (3) Xiao Liu pays 470 yuan in taxes, then the manuscript fee is 470 14% + 800 = 3357 + 800 = 4157, so some of them should be taxed according to 11. Assuming that the 11% part of the tax is x, then (4000-800)*14%+x*11%=470, x=200, so Xiao Liu's manuscript fee is 4200

1. 1/2x=1/4x+24 x=96

2.Pears: x apples 3 2x

x+3/2x=150

x=60 apple: 90

What I didn't read was.

1 5/9 4/9

This book is altogether.

50 (5/9 4/9) 450 pages.

4. Storybook 270 2 3 = 135

1 bottle is 1 7 8 = 1 56 of a bucket of water

A full 7 bottle is 1 56 * 7 = 1 8 for a bucket of water

56 (7 8) = 64 kg.

The bucket weighed 64 kilograms.

I'm so tired of typing, ahhhhh

1. 1/2x=1/4+24

2.Pears: x apples 3 2x

x+3/2x=150

Others are not happy to do.

1。The most economical material should have the largest overlapping area, and the area of length and width should be the largest, so the length and width should coincide s=2No.

Length 18, width 14, volume 1512, then height 6. Even though 18 and 14 are fine, 6<8, i.e., the container to be filled cannot be put in any way.

3.From the question to know the bottom area, the water is 1m high. The depth of the pool, the water surface is meters away from the mouth of the pool (to correct the problem, it should be 34 cubic meters).

1, (1) 2 * [(square centimeter (2) 2 * [(square centimeter (3) 2 * [(square centimeter.

Answer: The length remains the same, the width remains the same, and the height is increased to 4 times The most economical material, at least square centimeters of wrapping paper are required2, A: No.

1512 18 14 = 6 cm, 8 cm >> 6 cm doesn't.

3. There is no mistake in the water is 34m If the water is 34 cubic meters 34 Answer: The water surface is meters away from the mouth of the pool.

.2+ dmm.

Specifically, it can be seen that there are two semicircles on both sides, and in the middle are the diameters of two rubber stools of Liang Bilu.

2. In one day and night, the hour hand has gone twice times.

2* square centimeters.

The area covered by the hour hand is 5652 square centimeters.

3. The circumference of Hui contains a square paper of 4 cm, and the side length = 4 4 = 1cm1 * square centimeter.

The area of the remaining part is a square centimeter.

1. If the duck is regarded as 1 part, then the chicken has 4 parts, then 135 corresponds to 3 times that of the duck, so the duck has 135 (4-1) = 45 (only), and the chicken has 45 + 135 = 180 (only). This is a "difference multiple problem", where difference multiple difference = decimal place.

2. If the pear is regarded as 1 part, then there are 8 parts of the apple, then 128 boxes correspond to 9 times the pear, so the pear has 128 (1+8) = 128 9 (box), 128-128 9 = 1024 9 (box). This is a "sum problem", and multiples sum = decimals. (By the way, 128 is not a mistake)

3. Because the dividend = divisor quotient + remainder, the dividend can be written as "divisor 8+1" according to the known conditions. And because the dividend + divisor + quotient + remainder = 118, then (divisor 8 + 1) + divisor + 8 + 1 = 118, so the dividend = (118-1-8-1) (1 + 8) = 12, the dividend = 12 8 + 1 = 97

4. According to the known conditions, the price of two basketballs is 200 yuan. Column formula (570-370) (5-3) = 100 (yuan).

5. "Removing the 0 on the single digit of the number A equals the number B" means that "the number A is 10 times the number B", and the method of this question is the same as the second question. Then the number B is 253 (10+1)=23, so the number A is 23 10=230

6. "The rest is just equal to the weight of the original two boxes", which means that "the poured out is just equal to the weight of the original six boxes", so the original average weight per box is 15 8 (8-2) = 20 (kg).

7. The solution method is the same as that of question 2, longan tree: 480 (1+3)=120 (trees), mango tree 120 3=360 (trees).

8. If the other factor is not wrong, then the wrong result is actually (21-12) times less than the correct result of the factor that is not wrong, then the factor that is not wrong is 1107 (21-12) = 123, so the correct product is 123 21 = 2583

.There will be a first prize x and a second prize y.

If all 100 people win the third prize, the bonus is only 5000, which is 9500-5000=4500 yuan because I regard the first prize and the second prize as the third prize, that is, the first prize is 950 yuan less, and the second prize is 200 yuan less, so there is 950 x 200y=4500

x is not an integer.

When x=2, y=13. Y must be less than 5

So there are 13 people who won the second prize.

Question 1: If the number of chickens is x, then the number of ducks is 1 4 x, (1-1 4)x=135, and x=180, the number of chickens is 180, and the number of ducks is 180 4=45.

Question 3: Let the dividend be x and the divisor be y, and introduce the equation: x=8y+1, x+y+8+1=118, and bring x=8y+1 into the second equation, so that y=12, then x=8y+1=97