2,35 . x + 1,65 . x = 20

x.( 2,35 + 1,65 ) = 20

4x = 20

x = 20 : 4

x = 5

Vậy x = 5

Topic 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.

\(| \dfrac{3}{4} - \dfrac{1}{2}x| . \dfrac{2}{5} - 1\dfrac{1}{3} = 2\)

\(|\dfrac{3}{4} - \dfrac{1}{2}x| . \dfrac{2}{5} = 2 + \dfrac{4}{3}\)

\(|\dfrac{3}{4} - \dfrac{1}{2}x| . \dfrac{2}{5} = \dfrac{10}{3}\)

\(|\dfrac{3}{4} - \dfrac{1}{2}x| = \dfrac{10}{3} : \dfrac{2}{5}\)

\(| \dfrac{3}{4} - \dfrac{1}{2}x| = \dfrac{25}{3}\)

\(\dfrac{3}{4} - \dfrac{1}{2}x = \dfrac{25}{3}\) hoặc \(\dfrac{3}{4} - \dfrac{1}{2}x = \dfrac{-25}{3}\)

\(\dfrac{1}{2}x = \dfrac{3}{4} - \dfrac{25}{3}\) hoặc \(\dfrac{1}{2}x = \dfrac{3}{4} + \dfrac{25}{3}\)

\(\dfrac{1}{2}x = \dfrac{-91}{12}\) hoặc \(\dfrac{1}{2}x = \dfrac{109}{12}\)

\(x = \dfrac{-91}{6}\) hoặc \(x = \dfrac{109}{6}\)

Vậy \(x = \dfrac{-91}{6}\) hoặc \(x = \dfrac{109}{6}\)

\(\dfrac{13}{15} + \dfrac {4}{7} - \dfrac{101}{105}\)

= \(\dfrac{91}{105} + \dfrac{60}{105} - \dfrac{101}{105}\)

= \(\dfrac{10}{21}\)

The picture 3 is very cute !!

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Tick mình với các bạn!

Diện tích hình vuông là

12 x 12 = 144 ( cm² )

Vậy diện tích hình vuông là 144 cm²

Khởi nghĩa Hương Khê diễn ra trong thời gian nào?

A. Từ năm 1885 đến năm 1896.

B. Từ năm 1885 đến năm 1890.

C. Từ năm 1884 đến năm 1894.

D. Từ năm 1886 đến năm 1896.