\(=\frac{1}{2}+-\frac{1}{3}+\frac{1}{4}+\frac{1}{-5}+\frac{1}{6}+-\frac{1}{2}+\frac{1}{3}+\frac{1}{-4}+\frac{1}{5}\)
\(=\left(\frac{1}{2}+-\frac{1}{2}\right)+\left(-\frac{1}{3}+\frac{1}{3}\right)+\left(\frac{1}{4}+\frac{1}{-4}\right)+\left(\frac{1}{-5}+\frac{1}{5}\right)+\frac{1}{6}\)
\(=0+0+0+0+\frac{1}{6}\)
\(=\frac{1}{6}\)

\(\frac{1}{2}+\frac{-1}{3}+\frac{1}{4}+\frac{1}{-5}+\frac{1}{6}+\frac{-1}{2}+\frac{1}{3}+\frac{1}{-4}+\frac{1}{5}\)

\(=\frac{1}{2}+\frac{-1}{3}+\frac{1}{4}+\frac{-1}{5}+\frac{1}{6}+\frac{-1}{2}+\frac{1}{3}+\frac{-1}{4}+\frac{1}{5}\)

\(=\left(\frac{1}{2}-\frac{1}{2}\right)+\left(\frac{1}{3}-\frac{1}{3}\right)+\left(\frac{1}{4}-\frac{1}{4}\right)+\left(\frac{1}{5}-\frac{1}{5}\right)+\frac{1}{6}\)

\(=0+0+0+0+\frac{1}{6}\)

\(=\frac{1}{6}\)

= 1 / 6 nha bạn

C = 1/3 + -3/4 + 3/5 + 1/57 + -1/36 + 1/15 + -2/9

C = ( 1/3 + 1/57 ) + ( -3/4 + -1/36 ) + ( 3/5 + 1/15 ) + -2/9 

C = ( 19/57 + 1/57 ) + ( -27/36 + -1/36 ) + ( 9/15 + 1/15 ) + -2/9 

C = 20/57 + -28/36 + 10/15 + -2/9 

C = 20/57 + -7/9 + 2/3 + -2/9

C = ( 20/57 + 2/3 ) + ( -7/9 + -2/9 )

C = 58/57 + -1 

C = 1/57

D = 1/2 + -1/5 + -5/7 + 1/6 + -3/35 + 1/3 + 1/41

D = ( 1/2 + 1/3 + 1/6 ) + ( -1/5 + -5/7 +-3/35 ) + 1/41

D = ( 3/6 + 2/6 + 1/6 ) + ( -7/35 + -25/35 + -3/35 ) + 1/41

D = 1 + -1 + 1/41

D = 1/41

E = -1/2 + 3/5 + -1/9 + 1/127 + -7/18 + 4/35 + 2/7 

E = ( -1/2 + -1/9 + -7/18 ) + ( 3/5 + 4/35 ) + 1/127 + 2/7

E = ( -9/18 + -2/18 + -7/18 ) + ( 21/35 + 4/35 ) + 1/127 + 2/7

E = -1 + 5/7 + 1/257 + 2/7 

E = -1 + ( 5/7 + 2/7 ) + 1/127

E = -1 + 1 + 1/127

E = 1/127

\(C=\frac{1}{3}+\frac{-3}{4}+\frac{3}{5}+\frac{1}{57}+\frac{-1}{36}+\frac{1}{15}+\frac{-2}{9}.\)

\(C=\left(\frac{1}{3}+\frac{3}{5}+\frac{1}{15}\right)-\left(\frac{3}{4}+\frac{1}{36}+\frac{2}{9}\right)+\frac{1}{57}\)

\(C=1-1+\frac{1}{57}\)

\(C=\frac{1}{57}\)

D=1/2+-1/5+-5/7+1/6+-3/35+1/3+1/41

D=(1/2+1/6+1/3)-(1/5+3/35+5/7)+1/41

D=1-1+1/41

D=1/41

E=-1/2+3/5+-1/9+1/127+-7/18+4/35+2/7

E=(3/5+4/35+2/7)-(1/2+1/9+7/18)+1/127

E=1-1+1/127

E=1/127

A=\(\frac{\frac{3}{7}-\frac{3}{17}+\frac{3}{37}}{\frac{5}{7}-\frac{5}{17}+\frac{5}{37}}+\frac{\frac{1}{2}-\frac{1}{3}+\frac{1}{4}-\frac{1}{5}}{\frac{7}{5}-\frac{7}{4}+\frac{7}{3}-\frac{7}{2}}\)

\(=\frac{3\left(\frac{1}{7}-\frac{1}{17}+\frac{1}{37}\right)}{5\left(\frac{1}{7}-\frac{1}{17}+\frac{1}{37}\right)}+\frac{\frac{1}{2}-\frac{1}{3}+\frac{1}{4}-\frac{1}{5}}{-7\left(\frac{1}{2}-\frac{1}{3}+\frac{1}{4}-\frac{1}{5}\right)}\)

\(=\frac{3}{5}+\frac{1}{-7}=\frac{3}{5}-\frac{1}{7}\)

\(=\frac{21}{35}-\frac{5}{35}=\frac{16}{35}\)

Phần 1)Đầu tiên bạn nhân B với 1 phần 4 rồi tính đến đoạn gần cuối sẽ ra 1/3 - 1/35 rồi quy đòng rồi tính sẽ ra kêt quả cuối là 32/105 nha

Mình lười lắm nên chỉ help 1 phần thui nha sr

giúp đi mà

\(\frac{0,125-\frac{1}{5}+\frac{1}{7}}{0,375-\frac{3}{5}+\frac{3}{7}}+\frac{\frac{1}{2}+\frac{1}{3}-0,2}{\frac{3}{4}+0,5-\frac{3}{10}}\)

= \(\frac{\frac{1}{8}-\frac{1}{5}+\frac{1}{7}}{\frac{3}{8}-\frac{3}{5}+\frac{3}{7}}+\frac{\frac{2}{4}+\frac{2}{6}-\frac{2}{10}}{\frac{3}{4}+\frac{3}{6}-\frac{3}{10}}\)

= \(\frac{\frac{1}{8}-\frac{1}{5}+\frac{1}{7}}{3.\left(\frac{1}{8}-\frac{1}{5}+\frac{1}{7}\right)}+\frac{2.\left(\frac{1}{4}+\frac{1}{6}-\frac{1}{10}\right)}{3.\left(\frac{1}{4}+\frac{1}{6}-\frac{1}{10}\right)}\)

= \(\frac{1}{3}+\frac{2}{3}\)

= \(\frac{3}{3}\)

= 1

=1 nhé bạn

câu trả lơì là 1

\(\frac{1}{2}\times\frac{1}{2}+\frac{1}{2}\times\frac{1}{3}+...+\frac{1}{5}\times\frac{1}{6}\)

\(=\frac{1}{4}+\frac{1}{2\times3}+\frac{1}{3\times4}+\frac{1}{4\times5}+\frac{1}{5\times6}\)

\(=\frac{1}{4}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}\)

\(=\frac{1}{4}+\frac{1}{2}-\frac{1}{6}\)

\(=\frac{3+6-2}{12}=\frac{7}{12}\)

\(\frac{1}{2}\)* \(\frac{1}{2}\)+ \(\frac{1}{2}\)*\(\frac{1}{3}\)+ \(\frac{1}{3}\)* \(\frac{1}{4}\)+ \(\frac{1}{4}\)* \(\frac{1}{5}\)+ \(\frac{1}{5}\)* \(\frac{1}{6}\)

=\(\frac{1}{2}\)* \(\frac{1}{6}\)= \(\frac{1}{12}\)

( Những phân số khác nhau bạn loại đi nhé tại mình ko làm được bước đó trên này bạn thông cảm nhé ! ) 

\(\frac{1}{2}\times\frac{1}{2}+\frac{1}{2}\times\frac{1}{3}+...+\frac{1}{5}\times\frac{1}{6}\)

\(=\frac{1}{4}+\frac{1}{2\times3}+\frac{1}{3\times4}+\frac{1}{4\times5}+\frac{1}{5\times6}\)

\(=\frac{1}{4}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}\)

\(=\frac{1}{4}+\frac{1}{2}-\frac{1}{6}\)

\(=\frac{7}{12}\)

C = 1/100 - ( 1/2.1 + 1/3.2 + ... + 1/98.97 + 1/99.98 + 1/100.99

C = 1/100 - (  1- 1/2+ 1/2 - 1/3 + ... + 1/97 - 1/98 + 1/98 - 1/99 + 1/99 - 1/100 )

C = 1/100 - ( 1 - 1/100 )

C = 1/100 - 99/100

C = \(\frac{-49}{50}\)

(2/5+2/7-2/11):(3/7-3/11+3/5) =2/5+2/7-2/11.7/3-11/3+5/3=2/1+2/1-2/1.1/3-1/3+1/3=2+1/3=7/3                                                                          Em đây mới học lớp 6 nên hay xem kĩ lại và tính bang máy tính  

a, 2/3

b,1

nhớ nhé