Two elementary school math problems! Urgent!! About proportions

3. Solution: The actual length of the part is x centimeters.

20：x=10：1

x=2A: (omitted).

4. Solution: The actual length from Beijing to Hangzhou is x centimeters.

x=1：26000000

x=114400000

114400000 cm = 1144 km.

A: (omitted).

The meaning of the scale bar is the measured length of the figure: the actual measured length. So the answer is.

3.The length of the part is 2 cm.

4.The actual length from Beijing to Hangzhou is 1144 kilometers.

3. 20 cm x 10 = 200 cm.

4. Centimeter x 26000000 = 114400000 cm = 1144000 meters = 1144 kilometers.

It is 2cm absolutely!

I'm in junior high 2.

The second question is 1144 km!! Right!!!

Fill-in-the-blank question (1) The ratio of the four factors of 18 is two ratios of two-thirds, and the ratio is composed of (2:3=6:9) (2) If 3 three-sevenths 9 one-seventh, then (3):(9) (1 7):(3 7).

3) If 4a 5b, then a:b (

a, b is not 0).

True/False (1) When a:b 1 and one-third, then 3a 4b (right) (2) If sevenths m is equal to n-sevenths, then m:n 1:1 (

Solution: Set 12 gray magpies to protect x hectares of forest:: As a result, x this pair.

I think what you did should be right, I did the math, and the result is the same as you: the number of hectares, 10,000 is the number of insects, it is the number of hectares of forest that can be protected for every 10,000 insects eaten, x is the number of hectares, and 10,000 is the number of insects, so that the equation is formed, if you use 12, 12 is the number of magpies, the calculation should be the forest that each magpie protects in a year, and it calculates the forest that can be protected for every 10,000 insects eaten. (By the way, I'm also in the sixth grade, so I'm under a lot of pressure for exams).

Question: Two-thirds of bag A weighs the same as three-quarters of bag B, that is, 2 3 A = 3 4 B, then A: B = 3 4:2 3 = 3 4 * 3 2 = 9:8

That is, the mass ratio of the two bags of rice A and B is 9:8

If the B bag of rice weighs 16kg, then A:B = 9:8=A:16 then A is 18.

So the bag of rice weighs 18 kg.

(1) Proportional.

2) Set the shadow length to x meters.

1 division is equal to x

The solution is equal to 14

A: The shadow length is about 14 meters.

3) Set the tree height to Y meters.

1 divided by 4 equals y division.

The solution is that y is equal to 8

A: The tree is 8 meters high.

Convert Chinese characters into mathematical language yourself, I won't type).

① 180：300=3：x

x = 5 km.

8:6=24：x

x = 18 boxes.

16：15= x：12

x = 20 people.

160: 4 = 40 sets.

360：x=40

x = 9 days. 12：40=x：60

x = 18 tons.

120 tons = 120,000 kg 500:25 = 120,000:xx = 6,000 kg 6,000 kg = 6 tons 40:

312=x:1248 x=160 cubic meters 20:600=30:

x x = 900 Ben 3: 150 = 10: x x = 500 m 500 + 150 = 650 m.

Ten. 75:40=60:x x=50 days.

Solution: If you can travel 300 kilometers in x hours.

180：3=300：x

180x = 3×300

x=900÷180

x= 5

Are you a fool? You don't look like a first-grader, don't you?

(2) and

and 281) Great Circle Radius: Small Circle Radius = (4) :(3).

2) Circumference of a large circle: Circumference of a minor circle = (4) :(3).

3) Great circle area: small circle area = (16) :(9).

1.(2) can be (1 3) (1 2) = 2 3:3 because of

4:3 (2 factions) About 2 factions.

16:9 (2 r 2) About 2

1, (2) and (3) are equal to the outer product according to the product of the inner term.

These three numbers form a ratio, and the optional numbers are (3 branches). Fierce knowledge.

4:9=28 Loss 9:7

8.Set up X people in team A and y people in team B.

x:y=7:3;x-30:y=3:2;x=84;y=36 Question 9.; x=15;

Question 10 (3k-5) (k-5)=4 1 solution k=15; 40 left; 10 Of all, there were 50 left.

Hope! Best wishes

Dizzy, why do you have so many Olympiad questions? Why don't you do your own research?

7x-30): 3x=3:2 x=12 A84 B36

x-10)+(x-8)=x-3 x=15 There are 15 questions in total.

3x-5=4(x-5) x=15 4x-10=50 There are 50 left.

Question 8, A against 84 people, B team 36 people.

There are 15 questions in the ninth question.

Question 10, there are 50 in total.

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