help me bài 3+4
p/s:thank you so much
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\(x\times\dfrac{20}{11}=\dfrac{1}{1}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{7}+\dfrac{1}{7}-\dfrac{1}{9}+\dfrac{1}{9}-\dfrac{1}{11}\\ x\times\dfrac{20}{11}=\dfrac{10}{11}\\ \Rightarrow x=\dfrac{1}{2}\)
Ta có :
=> X x 20/11 = ( 1 - 1/3 ) + ( 1/3 - 1/5 ) + ( 1/5 - 1/7 ) + ( 1/7 - 1/9 ) + ( 1/9 + 1/ 11 )
=> X x 2/11 = 1 - 1/11 = X x 1/11 = 11/11 - 1/11
=> X x 20/11 = 10/11
=> X = 10/11 : 20/11
=> X = 1/2
Most of the air pollution results from the burning of fossil fuels, motor vehicles, factories, aircraft and rockets. This can cause acid rain which damages water, soil, and vegetation. Air pollution also contributes to the greenhouse effect which can lead to a series of environmental problems such as global warming, polar ice melting, rise of sea levels and loss of land.
Water pollution is a result of dumping pollutants such as detergents, pesticides, oil, and other chemicals in rivers, which makes the water unclean or contaminated. Rubbish blockages in rivers can also cause pollution.
1. She asked me if I could help her with her bags the following day.
2. If Nam were a teacher, he would help you.
3. Nam ate too much so he was full.
4. They asked Nam if he liked watching movies.
P/S : câu 4 "you" chứ cậu
1. "Can you help me with my bags tomorrow " she said
=> She asked me if I could help her with her bags the following day
2. If/Nam/be/teacher/He/help/you
=> If Nam were a teacher , he would help you
3. Nam was full because he ate too much ( so)
=> Nam ate too much so he was full
4. " Do they like watching movies, Nam" they said
=> They asked Nam if they liked watching movies
Helpp mee
VD:
- Khi không khí là chất cách điện: Bình thường khi ta đứng gần ổ điện, ta không bị điện giật. Điều đó chứng tỏ không khí ở điều kiện bình thường là chất cách điện
- Khi không khí là chất dẫn điện: Khỉ các đám mây giông phóng điện xuống đất (hiện tượng sét đánh) thì không khí khi đó là chất dẫn điện
Dài thế! nguyễn triệu minh
miyano shiho A - B ko phải là -y2 mà là -3y2 nhé, chắc bn làm nhầm rồi!!