12-a

b.0,09

364 V

đề bài là gì vậy

B1: Chia 5 đồng tiền xu làm 3 nhóm:nhóm 1 và nhóm 2 mỗi nhóm có 2 đồng,nhóm 3 có 1 đồng.

B2: Đặt các nhóm 1 và 2 lên 2 đĩa cân:nếu cân thăng bằng thì đây là 4 đồng tiền thật,ta chỉ việc lấy 1 đồng tiền trong 4 đồng tiền đó.Nếu cân không thăng bằng thì ta sẽ lấy đồng tiền ở nhóm 3.

 half agree with this opinion. Why? 

Schools have considered the second house where the children can study, play and join the extracurricular activities. In the (bỏ)school, the student can learn all the subjects to expand their knowledge, do the exams... and especially, they can play with their friends. But sometimes, study too much make them feeling stress, yeah, I know this

Study on Internet has some advantages: they can learn by the (bỏ)photos, stories, songs... and they can stop when they want. But, it has many disadvantages. The children are too young to choose the information on Internet, which need to know or needn't. The Internet has many temptations like games,  cartoons... make them can't focus on study if their parents won't monitoring them, use too much or to the long time the electronic device can make their eyes have many problems.

for many reasons, the Internet just helps 40 percent of the children in the study. I think schools have many advantages than study on the Internet

Rút gọn phân số (-14).11+14.2/11.21-7.22

(-14).11+14.2/11.21-7.22

 =-154+28/231-154

=-126/77

=-18/11

ô ki cô

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