`2/[1xx5]+2/[5xx9]+2/[9xx13]+....+2/[93xx97]+2/[97xx101]`

`=1/2xx(4/[1xx5]+4/[5xx9]+4/[9xx13]+....+4/[93xx97]+4/[97xx101])`

`=1/2xx(1-1/5+1/5-1/9+1/9-1/13+...+1/93-1/97+1/97-1/101)`

`=1/2xx(1-1/101)`

`=1/2xx100/101`

`=50/101`

bn ghi rõ đc ko ạ mik ko hiểu lắm c.ơn bn

đề đâu bạn

\(\Rightarrow x+3\ge4\\ \Rightarrow x\ge1\)

\(\left|x+3\right|\ge4\)

\(\Leftrightarrow\left[{}\begin{matrix}x+3\ge4\\x+3\le4\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}x\ge1\\x\le1\end{matrix}\right.\)

365-(120+80-365-350)

https://hoc24.vn/cau-hoi/.7405828739440

1 Lan goes to the supermarket on foot

2 Our garden has many flowers

3 He has black hair

4 We don't have to finish the task today (not necessary => don't have to: không cần làm gì, còn must not là không được làm gì nên câu này đề cho must là sai)

5 Are there 23 students in your class?

6 Lan is not as young as Minh

X = -2/5- 3/10

X= -7/10

1: \(a^2-4b^2=\left(a-2b\right)\left(a+2b\right)\)

2: \(16a^2-b^4=\left(4a-b^2\right)\left(4a+b^2\right)\)

3: \(4a^4-81b^4=\left(2a^2-9b^2\right)\left(2a^2+9b^2\right)\)

\(a,-\left|2x-3\right|\le0,\forall x\Leftrightarrow-\left|2x-3\right|+3\le3\)

Dấu \("="\Leftrightarrow x=\dfrac{3}{2}\)

\(b,-\left|2-3x\right|\le0,\forall x\Leftrightarrow-\left|2-3x\right|-5\le-5\)

Dấu \("="\Leftrightarrow x=\dfrac{2}{3}\)

a: \(A=-\left|2x-3\right|+3\le3\forall x\)

Dấu '=' xảy ra khi \(x=\dfrac{3}{2}\)

b: \(B=-\left|2-3x\right|-5\le-5\forall x\)

Dấu '=' xảy ra khi \(x=\dfrac{2}{3}\)

cảm ơn bn nhìu