Help solve a few math problems, just the equation

1.Let A x person then B x (5 3).

2*（x-14）= x/（5/3）+14

x=302.Set a total of x people, male = , female =

x=803.If the distance between the two cars is x kilometers, then the sum of the speeds of the two cars is x 7x - 2*(x 7) = 210 + 360x = 7984Because the express train takes 6 hours to cover the whole journey, the full journey is 6 = 20 hours.

If the slow train takes x hours, the fast train will travel 1 20 times per hour, and the slow train will take 1 x the whole journey.

1/20+1/x）*12 = 1

x=30 is finished.

1: x= 5/3 y

x-14) (y+14)=1 2 The simultaneous solution gives x= , and now x+142: x y=2 3 (y-8)=x5 4 finds x+y=3: let v1 v 2 s

7 v1+7 v2= s

9 v1+360=s v1= ？ s

9v2+210=s v2=? s

The last two forms are used to find s=

4 : Set v1 v2 s

12 v1+ 12v2= s

6 v1 = s 3/10

Find t1=s v1 = 20 t2= s v2 = 30

The first floor is very good. bar.

1.Answer: 1 in 8, 5 out of 8, 5 out of 8.

2.Answer: B, A

3.A: 64 yuan.

4.A: 15 pcs.

5.A: The range is 15 meters and is placed in the center of the circle.

6.（1）.Answer: 45 pages.

2）.Answer: Sixteen out of sixty-one.

7.Answer: m.

What grade is this? Like the Elementary School Olympiad, o( o haha . My junior high school ( lalala.

1 2 of the number of people in the art group is 1 3 of the number of people in the calligraphy group, and the number of people in the art group: the number of people in the calligraphy group = 2:3

1 4 of the number of calligraphy group is 1 5 of the number of people in the sports group, and the number of calligraphy groups: the number of people in the sports group = 4:5

Number of people in the art group: Number of people in the calligraphy group: Number of people in the sports group = 8:

12:15Number of people in the art group: 140 (8+12+15) 8=32 people in the calligraphy group:

140 (8+12+15) 12=48 people in the sports group: 140 (8+12+15) 15=60 people.

There are x people in the art group, y people in the calligraphy group, and z people in the sports group, according to the theme.

x/2=y/3，y/4=z/5，x+y+z=140

The solution yields x=32, y=48, z=60

There are 12x people in the calligraphy group, 8x people in the art group, and 15x people in the sports group.

12+8+15)x=140, the solution is x=4

Therefore, there are 32 people in the art group, 48 people in the calligraphy group, and 60 people in the sports group.

Sports: 140x2+3+5 5=70

Calligraphy: 140x2+3+5 3=42

Art: 140x2+3+5 2=28

I guess that's right.

Solution: Set up art group x people, calligraphy group y people, sports group z people, there are:

Synoptic: x+y+z=140

1/2x=1/3y

1 4y=1 5z has:

x=2/3y

z=5/4y ∴x+y+z=2/3y+y+5/4y=140

Solution: y=48

x=24z=60

A: There are 24 people in the art group, 48 people in the calligraphy group, and 60 people in the sports group.

Solution: If there are x people in the calligraphy group, there are 2 3x people in the art group and 5 4x people in the sports group.

x+2/3x+5/4x=140

35/12x=140

x=48 (person).

Art group: 2 3x=2 3 48=32 (person) Calligraphy group: 5 4x=5 4 48=60 (person) Answer: . .

It's pretty simple, hehe.

There are x people in the art group, 3 2x people in the calligraphy group, and 15 8xx+3 2x+15 8x=140 in the physical education group

The solution is x=32, so 3 2x=48 people, 15 8x=60 people.

So there are 32 people in the art group, 48 people in the calligraphy group, and 60 people in the sports group.

Set up the art group x people, the calligraphy group y people, and the sports group is 140-x-y people 1 2x=1 3y, 1 4y=1 5 (140-x-y).By x=2 3y, substituting y=48, thus x=32Answer: 32 people in the art group, 48 people in the calligraphy group, and 60 people in the sports group.

There are 32 people in the art group, 48 people in the calligraphy group, and 60 people in the sports group.

Round bucket volume Bottom area Height Square of the radius of the bottom height Height becomes half, volume is less than half! However, the diameter of the bottom surface has been changed to 2 times, and the bottom area has become 4 times!

The overall volume becomes the original: multiple!

Therefore, the original volume can be loaded: 40 2 20 kg.

Total formula: 40 (2 2 2) 40 2 20 (kg).

Let the original bottom diameter x and height y, then the current bottom diameter is 2x and high.

Original volume: (

Now volume: (x).

Now the volume is twice as large as the original, and the mass of the water is also twice as large, so the original bucket is 20kg of water

Note] You can't directly list the equation of 40 for volume, because the units are different, and you will be deducted points during the exam.

After the bottom diameter is changed to 2 times of the original, the bottom surface machine is 4 times the original, and the height is changed to half of the original 1 2

20 (kg).

A: The original bucket can hold 20 kg of water.

Half the height, half the volume! However, the diameter of the bottom surface has been changed to 2 times, and the bottom area has become 4 times!

The overall volume becomes the original: multiple!

Circular bucket volume Bottom area Height The square of the radius of the bottom surface is v= r*r*h

After rectification, v2== 2r*2r*h 2=2vv=40 2=20kg

Solution: Let the radius of the bucket be r and the height be h, then the radius of the bucket is 2r and the height is h 2

The capacity of the original bucket = r 2*h

The capacity of the current bucket = (2r) 2*(h 2)=2 r 2*h=40 r 2*h=20

The original one can hold up to 20kg. Method:

Let the diameter of the original bucket be d and the height be h, then the changed diameter will be 2d and the height will be h 2.

The volume of the original bucket was (d 2) 2*h= d 2*h 4 and the volume of the later bucket was (2d 2) 2*h 2= d 2*h 4=40.

The original volume is half of the later volume, which is 20.

1.Calculate the volume of water in b Volume = length, width, height = 10 6 4 = 240 centimeters.

Then calculate the depth of water put into a Height = volume Length Height = 240 8 5 = 6 cm.

2.Because the side is square, the bottom side length = height = 16 cm, and because the bottom surface is a square, the side length of the square = the bottom side length 4=16 4=4 cm.

So length = width = 4 cm.

Volume = length, width, height = 4 4 16 = 256 cubic centimeters 3Set: 6 grains are counted x times, and 5 are left; 8 seeds and 8 seeds counted y times, and the remaining 7 pieces get: 6x+5=8y+7

So 3x-4y=1

When x=3 and y=2 satisfies the above equation and conforms to the topic, and the amount of sugar is the least at this time.

There are at least 23 pieces of sugar.

Question 1: The volume of water in container B 10*6*4=240 poured into A then 240 (8*5)=6

Question 2: Because the height is 16 and the side is square, it means that the sum of the length of the four bottom edges is 16, then the volume is 4*4*16=256

Question 3: It is equivalent to a number, divided by 6 and left for 5, divided by 8 and left for 7.

Let 6x+5=8y+7 6x=8y+2x, where y is an integer; Therefore, x=0 rounding, x=1 rounding, x=2, rounding, x=3, y=2, so the minimum value is 6*3+5=23

The volume of water in a container is 10*6*4=240, the ground of a container is 8*5=40, and the water in a is 240 40=6

2.If the height is 16 and the side is square, the circumference of the bottom square is 16, the side length of the square is 4, and the volume = 16 * 4 * 4 = 256

3.If you add one, the number of 6 and 8 and 8 and 8 are exactly counted, and the least common multiple of 6 and 8 is 24, minus one is 23.

1-- 10x6x4 (8x5)=6 cm2-- length of the cuboid = width 16 4=4 cm , v=4x4x16=256

3-- In other words, it should be: 5 is 6-1, 7 is 8-1 to borrow the saying that xhy doesn't drink-" Then add one, and you will be counted exactly 6 and 6 and 8 and 8, and the least common multiple of 6 and 8 is 24, and 24 is the smallest that can count 6 and 8 at the same time.

But when you count them all, you add "one". So:

The least number is --6x4 -1=8x3 -1 =24-1 =23

The result of the first question is 6 cm, and the equation is 10*6*4 8 5=6

The volume of the second question is 256 cubic centimeters, and the length and width are both 4 centimeters. Length and width are calculated as 16 4 = 4 cm, and volume is 4 * 4 * 16 = 256 cubic centimeters.

The third question is 23 pieces, and the remaining 5 and 7 pieces can also be understood as 1 less and exactly divided, so the number of candies is at least the least common multiple of 6 and 8 24 and then subtract 1, which is 23.

(6*10)*4=(5*8)*x x=6

The side square means that the circumference of the square on the bottom surface is 16, so the width of the cuboid is 4, and the volume is the base area multiplied by the height = 4 * 4 * 16 = 256

The last one is dizzy, look at the master.

*6*4=240 (cubic centimeters).

240 (8*5)=6 (cm).

4 = 4 (cm).

4*4*16=256 (cubic centimeters).

A: The volume is 256 cubic centimeters, and the length and width are both 4 centimeters.

240cm2=240ml 8*5=40cm 240 40=6cm length 4 width 4 volume 4*4*16=2563There are 5 left, 7 left, that is, 6 is less than one, and 8 is 1 less [6,8] = 24 24-1 = 23

10*6*4=240 (cubic centimeters).

240 (8*5)=6 (cm).

The side square means that the circumference of the square on the bottom surface is 16, so the width of the cuboid is 4, and the volume is the base area multiplied by the height = 4 * 4 * 16 = 256

6x+5=8y+7

When y=1, x=5 3

When y=2, x=3 (integer).

The total number brought in was 23

The volume of water in the container is: 10 6 4 = 240 cm3 Find a container water depth: 240 (8 5) = 6 cm2

It can be seen that the circumference of the bottom square is 16cm, then the length and width of the cube are 4cm, and the volume is: 4 4 16=256cm3

3.At least 23 of them.

The volume of toothpaste used each time: 3*(

Volume for one day: 2*

Volume for 30 days, i.e. net content of toothpaste: 30*

The extruded toothpaste can be thought of as a cylinder, so the volume of each extrusion = 2 (r 2) 2*h= *

Net content = daily usage * number of days.

Net content = each dosage * number of times * number of people * number of days.

Net content =

It's pretty much the following:

Since 1l = 1000 cm3 to the power, 1ml = 1 cm3 l = sh = 3 x (2) 2 x 2 = power.

Hence the content of the power i.e. toothpaste is.

The unit on the first floor is wrong, which is the volume of a drop of water.

The length is normalized into a meter, and the calculated volume unit is l (liter), not ml1l = 1000ml

So the correct answer is yes.

1620ml on the second floor catches up with the amount of a large bottle of Coke.

Solution: 1. Let the speed of A be 7x, then the speed of B is 9x, then there is:

9x-7x=20, x=10, then the speed of A and B is 70 and 90 respectively

The distance between the two places = 7 * (70 + 90) = 7 * 160 = 1120km2, and if A is transported to B x tons of grain, there are:

80 + x) :(100-x) = 45 and 3 5 solution: x = 23200 233 = 99 and 133 233 (tons) 3, let ab two places be 5s apart, according to the known conditions, it can be known that the distance is 2s, and the distance is 3s, then there is 210-20% * (5s) = 2s, the solution is obtained.

s=70, then 5s=350km

That is, the distance between the two places is 350km