Math Problem Solving Proportions, in math problems, what is Proportional Knowledge Solution

One thing that must be done to make a scale is to convert the units, first convert kilometers into centimeters: 1050 kilometers = 105000000 centimeters.

In the second step, you can divide the converted units by centimeters: 105000000 So, the scale is 1:700000000

If you don't understand, you can ask.

Hope, thank you.

1) x: three and a half = three and a seventh: 4

Solution: 4x = three and a half and three and a seventh.

4x=7/2×22/4

x=77/16

2) Seven and a half::1

Solution: Seven and a half::1

x=seven and a half 1

x=15/2×9/5

x=27/2

3) x+1/8 of 30.

Solution: x+1/8 of 30.

x+30）×1

x+30x=204) on the map of Shanghai, the Huaihai Road is measured to be 2 cm, if the scale of the map is 1:200000, then how many kilometers is the actual distance of the Huaihai Road in Shanghai?

Solution: The solution of the equation.

Set: The actual distance of Huaihai Road in Shanghai is x

Centimeter. According to the inscription: 2:x

x=2×200000

x=400000

400,000 cm = 4,000 m = 4 km.

A: The actual distance of Huaihai Road in Shanghai is 4 kilometers.

Arithmetic solution. Solution: According to the question column:

400000 (cm).

A: The actual distance of Huaihai Road in Shanghai is 4 kilometers.

5) In the interest activities, the ratio of the number of students participating in painting to the number of students participating in physical exercise is 4:9, of which 24 students participated in painting, so how many students participated in physical exercise?

Solution: The solution of the equation.

Setting: There are x number of students participating in physical exercise. According to the inscription column:

24：x=4：9

4x=216

x=54A: There are 54 students who participate in physical exercise. Arithmetic solution.

A: There are 54 students who participated in physical exercise.

:1050km =:105000000cm =1:700000000 This is my teacher's teaching method That's right! Thank you. Fill in 5 zeros to the right of the last digit of the kilometer centimeter.

The scale problem should be replaced with a unit of rice.

10,500 km = 10,500,000 m.

Centimeter = meter. Scale bar is 10500000

The scale is 1:7000000000

<> look, dear. Good luck with your learning.

The ratio of two quantities is proportional when it is a fixed value. When the first product of two quantities is a fixed value, it is inversely proportional.

Set the unknowns, and then use the proportional relationship to establish the chaotic calendar equation is the proportional knowledge solution. For example, how many hours does it take for a car traveling at a certain speed to travel 100 kilometers in 2 hours, but to travel 500 kilometers? Set up a clear search for x hours, from the meaning of the title.

100：2=500：x

100x=1000

x=10 is a solution with proportional knowledge.

Rewrite the ratio of 3:7 = 15:35 to the fractional form 3 7 = 15 35

According to the basic nature of proportions, the multiplicative form is written as 3x35=7x15

See **, you can get the result according to the proportional calculation method.

The ratio of 1 2:12 is (1 30), the ratio of the simplest integer equal to its ratio is (1:30), and the ratio of two ratios is (2 5:).

2. Which group of four numbers can form a ratio? Write out the proportions of the composition.

1) 1 2 energy: 1=:2(2) 24 3/5 9 energy 24::(3 5).

3) 12 180 10 Can't (4) 1/6 3/4 1/2 1/4 1 1/4 Can 1 6; 1/4=1/2:3/4

1/30:1 2/5:12 = 1/30.

2) 9:: 3/5

3) It doesn't seem to be.

4) 1/2: 1/6 = 3/4: 1/2

1、 1/30； 1：30； 2/5：12=1：30。

2. (1) Yes, 1: : and so on.

2) Yes : 24=3 5:9 etc.

3) No, you can't. 4) Can 1 6:1 2=1 4:3 4 and so on.

1.The outer term of the ratio is ( , 3 ) and the inner term is ( 2, ) x = 14

Then b is called a, c (the proportional term or the geometric mean) b=6.

1.It is known that the outer term of the ratio is ( and 3 ) and the inner term is ( and 2 ) 2Write a ratio with ( 2:4=3:6 ), and write one.

3.It is known that with and 8 is the innermost term, write a proportional formula as (:4) (write one) 4

Knowing the ratio 3:7=6:x, then x is equal to (14)5

If a:b=b:c, which is b's =(a*c), then b is called a, c's (the middle of the proportion).

6.Knowing that b is a positive integer and b is the middle term of the ratio of 4 and 9, then b = (6).

1.From the perspective of mathematics, this is the use of proportional relationships in the knowledge of proportions.

2. Have you ever observed the trees on campus? You feel that the height of the tree is (positively) proportional to its age.

1.Proportional (projective theorem).

2.Disproportionate.

The first one is not known, and the second one is "positive" in proportion.

One and two are both proportional.

"Hello Dianyin", I'm glad to answer for you!

4: (2 and 2/3 (8/3)) = 18:125:

25/3 (8 and 1/3)) = 3:52The school bought a total of 168 basketballs and soccer balls, and the ratio of the number of basketballs and soccer balls was 5:

3.How many basketballs and soccer balls did you buy?

Solution: There are 168 (5+3) 5 105 (pieces) of basketballs bought, then there are 168 (5+3) 3 63 (pieces) of soccer balls bought: There are 105 basketballs bought, and 63 soccer balls bought.

3.Normally, the mass of water with the same volume is 25% greater than that of alcohol, and if there is a bucket of water with a mass of 25 kilograms, if the volume of a bucket of alcohol is equal to the volume of this bucket of water, what is the mass of this bucket of alcohol?

Solution: Assuming that the mass of alcohol is 1, then the mass of water according to the question is (1+25%).

Knowing that the mass of water is 25 kg, then the alcohol mass is 25 (1+25%) = 20 (kg).

A: The mass of this barrel of alcohol is 20 kilograms.

48/18

2.168x (5 8) for basketball, the rest for football kilograms, with 25x (4 5).

The number of girls in Class A is 60% of the number of boys, the number of students in Class A is a multiple of 8, and the ratio of boys to girls in Class B is 6:7

Class B is a multiple of 13.

79 can only be divided into two cases: 40 and 39.

So the two classes have a size of 40 and 39 respectively