Bài 1 : Tính

1) \(\frac{4}{7}-\frac{1}{14}+\left|\frac{-5}{21}\right|\)

2) \(\left|\frac{-2}{3}\right|-\frac{1}{2}+3\)

3) \(\left|\frac{7}{-4}\right|-\frac{5}{8}+\frac{-2}{3}\)

4) \(\frac{4}{5}+\left|\frac{-3}{2}\right|+\frac{1}{-4}\)

5) \(\left|\frac{-1}{4}\right|-3+\frac{3}{4}\)

6) \(\left|\frac{-1}{3}\right|-\frac{5}{4}+\frac{1}{5}\)

Bài 2 : Tìm x, biết :

1) \(x-\left|1\frac{1}{6}\right|=\frac{5}{21}\)

2) \(x+\left|-1\frac{2}{3}\right|=\left|-\frac{3}{4}\right|\)

3) \(\left|x-\frac{1}{3}\right|=\frac{5}{2}\)

4) \(\left|x+\frac{2}{3}\right|=0\)

5) \(\left|x+2\right|=\frac{1}{3}-\frac{1}{5}\)

6) \(\left|x-4\right|=\frac{1}{5}-\left(\frac{1}{2}-\frac{5}{4}\right)\)

7) \(\left|x-\frac{5}{4}\right|=-\frac{1}{3}\)

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E đang cần gấp, cảm ơn :)

\(A=2\frac{3}{7}:\left(-12\frac{1}{2}+15\frac{1}{7}\right).\left(3\frac{3}{10}\right)-\left(\frac{-34}{37}\right).\left(2\frac{1}{10}-4\frac{2}{5}\right)\)

\(B=-3\frac{1}{10}:\left(\frac{1}{2}-\frac{2}{5}\right)-2\frac{1}{28}:\left(\frac{2}{7}-\frac{3}{4}\right)\)

bài 2:Tìm x

a. \(-1\frac{2}{3}-\left|2x-1\right|:\frac{3}{5}=-2\)

b. \(\frac{x-7}{36}=\frac{-4}{7-x}\)

Mình đang cần gấp ai đúng mình tích cho 

Mia mình nộp rồi

Bài 1 : Tính

1) \(\frac{4}{7}-\frac{1}{14}+\left|\frac{-5}{21}\right|\)

2) \(\left|\frac{-2}{3}\right|-\frac{1}{2}+3\)

3) \(\left|\frac{7}{-4}\right|-\frac{5}{8}+\frac{-2}{3}\)

4) \(\frac{4}{5}+\left|\frac{-3}{2}\right|+\frac{1}{-4}\)

5) \(\left|\frac{-1}{4}\right|-3+\frac{3}{4}\)

6) \(\left|\frac{-1}{3}\right|-\frac{5}{4}+\frac{1}{5}\)

Bài 2 : Tìm x, biết :

1) \(x-\left|1\frac{1}{6}\right|=\frac{5}{21}\)

2) \(x+\left|-1\frac{2}{3}\right|=\left|-\frac{3}{4}\right|\)

3) \(\left|x-\frac{1}{3}\right|=\frac{5}{2}\)

4) \(\left|x+\frac{2}{3}\right|=0\)

5) \(\left|x+2\right|=\frac{1}{3}-\frac{1}{5}\)

6) \(\left|x-4\right|=\frac{1}{5}-\left(\frac{1}{2}-\frac{5}{4}\right)\)

7) \(\left|x-\frac{5}{4}\right|=-\frac{1}{3}\)

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E cần gấp lắm ạ, cảm ơn.

3.Tính hợp lí:

a,\(\frac{17}{5}.\frac{-31}{125}.\frac{1}{2}.\frac{10}{17}.\frac{-1}{2^3}\)

b,\(\left(\frac{11}{4}.\frac{5}{9}-\frac{4}{9}.\frac{11}{4}\right).\frac{8}{33}\)

c,\(\left(\frac{17}{28}+\frac{18}{29}-\frac{19}{30}-\frac{20}{31}\right).\left(\frac{-5}{12}+\frac{1}{4}+\frac{1}{6}\right)\)

4.Tìm tích:

a,\(\left(\frac{1}{2}+1\right)\left(\frac{1}{3}+1\right).....\left(\frac{1}{99}+1\right)\)

b,\(\left(\frac{1}{2}-1\right)\left(\frac{1}{3}-1\right).....\left(\frac{1}{100}-1\right)\)

c,\(\frac{3}{2^2}.\frac{8}{3^2}.\frac{15}{4^2}....\frac{899}{30^2}\)

AI CÒN THỨC THÌ GIÚP MIK VS,MIK ĐANG CẦN GẤP

Bài 1:

a, Cho S=\(\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+...+\frac{1}{9^2}\) .Chứng minh rằng \(\frac{2}{5}< S< \frac{8}{9}\)

b, Tìm x thuộc z để phân số \(\frac{x^2-5x-1}{x+2}\)có giá trị là số nguyên

c, Chứng minh rằng \(\left(\frac{7}{65}+1\right)\left(\frac{7}{84}+1\right)\left(\frac{7}{105}+1\right)\left(\frac{7}{124}+1\right)...\left(\frac{7}{153+1}\right)\left(\frac{7}{560}+1\right)< 2\)

d, Chứng minh rằng \(\frac{1}{3}-\frac{2}{3^2}+\frac{3}{3^3}-\frac{4}{3^4}+\frac{5}{3^5}-...+\frac{99}{3^{99}}-\frac{100}{3^{100}}< \frac{3}{16}\)

Bài 1: Tính nhanh

a) \(\frac{2}{3.5}\)+\(\frac{2}{5.7}\)+\(\frac{2}{7.9}\)+...+\(\frac{2}{19.21}\)

b) \(\left(1+\frac{1}{2}\right).\left(1+\frac{1}{3}\right).\left(1+\frac{1}{4}\right).....\left(1+\frac{1}{99}\right)\)

c) \(\frac{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{100}}{\frac{1}{99}+\frac{2}{98}+\frac{3}{97}+...+\frac{98}{2}+\frac{99}{1}}\)

Bài 2. Tìm x, biết:

a) \(\frac{x-2}{20}=\frac{5}{2-x}\)

b)  \(\left(\frac{x}{3}+\frac{1}{2}\right)\left(75\%-1\frac{1}{2}x\right)=0\)

Mk cảm ơn nhé. Các bn làm đc câu nào thì làm (nhất là b2)

1/ |x| =\(\frac{1}{5}\)

2/ |x|= - \(\frac{-5}{3}\)

3/ |x|= \(\frac{\left|-3\right|}{\left|2\right|}\)

4/ |x|= 3\(\frac{1}{5}\)

5/ |x -\(\frac{1}{2}\)|=\(\frac{\left|-6\right|}{\left|7\right|}\)

giúp mình giải cụ thể chi tiết ra nhé mình cần gấp lắm rồi cảm ơn