Air pollution in our country is one of the most serious environmental problems, and many major cities in our country are affected by it. Increasing carbon emission from industries and automobiles makes it worse every day. Other harmful particles produced from burning fossil fuel have made the situation graver.
The effects of air pollution are really dangerous. Air pollution in my country is responsible for many health-related problems among citizens, and also kills many people every year. It is liable for causing respiratory disorders and many people get sick who are exposed to air pollution for a long time. The usual short-term problems include difficulties in breathing, bronchitis, heart ailments and so on while it can lead to cancer or even death in the long run. Unfortunately, air pollution in our country is reducing the life expectancy of many peopleNo doubt, air pollution is a global problem now, and in my country, fossil fuels and rapid industrialisation are the primary reasons behind it. The excessive use of machinery and motorised vehicles ignites the rise of greenhouse gases in the atmosphere. Increasing dust particles make things more damaging.                                              Air pollution is a burning issue for our country now. Some cautionary measures should be taken to check the air pollution level. The most important step to reducing air pollution is to reduce carbon emissions. So we need to reduce the use of gas, oil and other fossil fuels. Alternative energy or green energy like solar energy, hydroelectric power and wind power should be used more extensively. A massive awareness among ordinary people about air pollution is also required to curb the problem.

Air pollution in our country is one of the most serious environmental problems, and many major cities in our country are affected by it. Increasing carbon emission from industries and automobiles makes it worse every day. Other harmful particles produced from burning fossil fuel have made the situation graver.
The effects of air pollution are really dangerous. Air pollution in my country is responsible for many health-related problems among citizens, and also kills many people every year. It is liable for causing respiratory disorders and many people get sick who are exposed to air pollution for a long time. The usual short-term problems include difficulties in breathing, bronchitis, heart ailments and so on while it can lead to cancer or even death in the long run. Unfortunately, air pollution in our country is reducing the life expectancy of many peopleNo doubt, air pollution is a global problem now, and in my country, fossil fuels and rapid industrialisation are the primary reasons behind it. The excessive use of machinery and motorised vehicles ignites the rise of greenhouse gases in the atmosphere. Increasing dust particles make things more damaging.                                              Air pollution is a burning issue for our country now. Some cautionary measures should be taken to check the air pollution level. The most important step to reducing air pollution is to reduce carbon emissions. So we need to reduce the use of gas, oil and other fossil fuels. Alternative energy or green energy like solar energy, hydroelectric power and wind power should be used more extensively. A massive awareness among ordinary people about air pollution is also required to curb the problem.

Gọi số học sinh cần tìm là x (x > 2 và x thuộc N*)

Từ đề bai suy ra (x-2) là bội của 10,12,15

Hay \(x-2\in BC\left(10;12;15\right)\)

=> \(\left(x-2\right)\in B\left(60\right)=\left\{0;60;120;180;240;300...\right\}\)

=> \(x\in\left\{2;62;122;182;242;302...\right\}\)

Mà 280 < x < 320 

=> x = 302

Vậy khối 6 có 302 học sinh

mình chỉ giải một ít thôi, do mấy cái này có trong sách hết đó

Nửa chu vi của hcn là: 

360 : 2 = 180 m 

Chiều dài của mảnh đất là: 

(180+28) : 2 = 104 m 

Chiều rộng của mảnh đất là: 

180 - 104 = 76 m

Diện tích của mảnh đất là: 

104 x 76 = 7904 m vuông

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Gọi x,y là số vòng quay của kim phú và kim giờ khi 10h cho tới lúc 2 kim đối diện nhau trên 1 đường thẳng, ta có:

          \(x-y=\dfrac{1}{3}\) (ứng với 12 số 4 trên đồng hồ)

Và x:y=12 (do kim phút quay nhanh gấp 12 lần kim giờ)

Do đó \(\dfrac{x}{y}=\dfrac{12}{1}\)

             \(\Rightarrow\dfrac{x}{12}=\dfrac{y}{1}=\dfrac{x-y}{11}=\dfrac{1}{3}:11=\dfrac{1}{33}\)

             \(\Rightarrow x=\dfrac{12}{33}=\dfrac{4}{11}\left(giờ\right)\)

Vậy thời gian 2 kim đồng hồ nằm đối diện nhau trên 1 đường thẳng là \(\dfrac{4}{11}\) giờ

Cần đợi thêm 8(h) để kim giờ và kim phút đối diện nhau trên 1 đường thẳng

Tổng chiều dài và chiều rộng là: 

35 x 2 = 70 m 

Chiều dài của khu đất là: 

(70+10):2= 40m

Chiều rộng khu đất là : 70-40= 30 m 

Diện tích khu đất là: 40 x 30 =1200 m vuông 

co cai nit