Primary 6 math is urgent, solve Primary 6 math problems

1: In the formula for the area of a circle, when s is constant, is it inversely proportional to r (disproportionate).

2: Scale 100:1, the distance in the figure (greater than, less than) Actual distance (greater than) 3: 200 meters long, 150 meters wide, on the drawing book, the scale bar selected is (1/200).

Choose 1 out of 2000

4;The scale of a map segment is 0-80-160-240 kilometers, and the scale is rewritten as a number.

1. A: Disproportionate.

2. Answer: The scale is 100:1, and the distance in the figure is greater than the actual distance.

3. Answer: 200 meters long, 150 meters wide, on the painting book, the scale of the selection is: 1/2000

4. Answer: The scale of a map line segment is 0-80-160-240 kilometers, and the scale of rewriting into numbers is (1:8000000).

1 is a constant, so it's not true.

2 The distance in the figure is greater than the actual distance.

3 1 in 200,000

4 1 in 8,000,000

1。When s is a fixed value, it is a fixed value, and r can only be a fixed value.

2。The distance in the figure is greater than the actual distance.

1.Not inversely proportional.

2.Greater than. 3 1/2000

1.No, because s (definitely) = the square of r. 1 out of 1

One is wrong, inversely proportional to the square of r.

Two: less than. Three: 1 in 2000.

Four: Do the math yourself.

1 No. 2 is greater than.

3 1/2000

4 I don't know what you mean.

In practice, A works for 25 days and B works for 16 days; It is equivalent to A and B working together for 16 days, and a total of 16 20 workload has been completed, that is, the remaining workload of 1 5, this part of the workload is equivalent to A working alone for 9 days, therefore, A needs 9 * 5 = 45 days to complete alone, then B needs 1 (1 20-1 45) = 36 days to complete.

Analysis: If the speed of the road construction of teams A and B is x and y, and this section of the road is regarded as unit 1, then it can be seen from the title.

1=20(x+y)

1=12x+13(x+y)+3y

Joining the above two equations, we can solve, x=1 45

y=1/36

Therefore, it will take 45 days and 36 days for teams A and B to complete this section of the road alone.

It takes X days for a team to build this section of the road alone.

Then A can repair 1 x section of this section of the road every day, B can repair 1 20-1 x A and B can repair 1 20 per day

It can be obtained from the title.

1 x ) x12 + 13 x1 20 + (1 20-1 x) x3 = 1 to get x = 45

It takes 45 days for A to repair alone, and 36 days for B.

Set A x day, B y day, then.

1/x+1/y=1/20

12+13)/x+(13+3)/y=1

The solution is x=45 and y=36

There is a problem with the topic.

It's less than 100 in total

of the master + the apprentice = 100???

So the side length of the small square is 1 2 of the hidden large square

The sum of the side lengths = 72 4 = 18

18 (1 2) (1+1 Yuanqiao 2) +6

Answer: The small square side stove is 6 cm long, and the large square side is 12 cm long.

Small square: 72 4 (1+2)=6

The side length of a large square = 6x2 = 12

1.Let Kaihe trap A speed is 5, B speed is 4, A stroke is A, B stroke is B, then.

b-a=45

b-72)/4=a/5

From the above equations, we can get a = 135 km, b = 180 kilometres, ab = a + b = 315 km.

2.Let the speed of A be 4, the speed of B be 5, the stroke of A is A, and the stroke of B is pure B, then.

b-a=45

b-72)/5=a/4

There is no solution to the above equations, so ab = 315 km.

I think it's a lot easier to use Zheng Kuan's arithmetic method:

The distance traveled by two cars, A is 72 45 27 kilometers more than B, then the distance traveled by two cars is .

27 (5 9 4 9) 243 thousand cavity meters;

With the 72 kilometers that B went first, the AB distance is.

243 72 315 km.

Solution: Let the velocity of A be 5x, the velocity of B is 4x, and the time when A begins to walk to meet and walk with B is t, then the following equation is:

45+5xt=4xt+72

So: xt=27

From the meaning of the title, it can be seen that the distance between abs is 5xt+4xt+72, so the distance between abs can be found to be 315 by bringing in the pre-source shield xt=27

Solution: Let the velocity of A be x, the velocity of B be y, and the distance of ab be z, then (x+y)*40=. y*（40+25）=z-60。

Solve the above equations and roll around, and get x=36 13, y=221 195, z=192Are you satisfied with this answer?

The above is done to scale.

All learning problems are found in the elite].

One hundred and sixty million eight hundred seventy seventy seven.

100 million, 973 points on the head.

4 80 VIII.

7 22 Two points on the head

One hundred and sixty million eight hundred seventy seventy seven.

Such a simple question, you can do it anyway!

The property of the eldest is one-half of that of the other two, and the property of the eldest of the jujube branch bucket is one-third of the three.

The property of the old two is one-third of that of the other two, and the property of the old two is a quarter of the three-person stool grinder.

The old one-third of the property was five-twelveth of the three.

The property left by the old man is 12000 5*12=28800