40 chai đựng đầu nặng ​34 kg 

trả lời: 345,4 cm²

bài 1:

a) (2x+1).y=12

<=>(2x+1)y-12=0

=>2x+1=0

=>2x=-1

=>2y=0

3.I live in Vietnam and there are a lot of traffic problems in big cities in my country. Firstly, there are too many people using the roads especially in the rush hour when people run out to work and school or get home from those places. Secondly, there are too many vehicles on the road that leads to traffic jams. Another problem is that many roads are narrow and bumpy. Fourthly, there are traffic accidents every day so a lot of people lose their lives or are injured. So in order to travel on the roads safely, I think we should obey the traffic rules and traffic signs as well. Moreover, carefulness is very necessary.

2.Environment is an essential part of our life. A clean environment is necessary for a peaceful and healthy life. An environment is the natural surroundings which helps human beings, animals and other living things to grow and develop naturally. But nowadays, our environment is disturbing in many different ways. Any type of disturbance in the nature’s balance affects the environment totally. It does not only ruin human lives but also affects on all living beings. We can save our environment with the little step taken by everyone on the earth. We should reduce the amount of waste, throwing wastes properly to its place only…and many other simple ways. It is very important to save environment for human existence. When we protect the environment, we are protecting ourselves and our future as well.

x=-504

ủng hộ mk nha các bạn

44099

ủng hộ mk nha các bạn

345,4 cm vuông hên xui nhé

olm duyệt đi

tuổi ông hiện nay là : 72 / ( 5+1) *5 =60 ( tuổi)

tuổi cháu hiện nay là : 72 - 60 =12 ( tuổi)

ông hơn cháu số tuổi là : 60 -12 =48  (tuổi) 

tuổi cháu khi cháu bằng 1 / 9 tuổi ông là : 48 / ( 9- 1) *1 =6(tuổi)

vậy trước đây số năm thì tuổi cháu = 1/9 tuổi ông là : 12 - 6 =6 (năm)

Đ/Số :6 năm 

duyệt mk nha các bn

tuổi cháu hiện nay là

72 : ( 5 + 1 ) = 12 tuổi

ông hơn cháu 

72 -12 - 12 = 48 tuổi

tuổi cháu lúc bằng 1/9 tuổi ông là

48 : ( 9 - 1 ) = 6 tuổi

trước đây

12 - 6 = 6 năm