giống bài mình cần mà ko có ai trả lời nhỉ

mong mọi người vô giúp 2 đứa mình với

B=81.(12.(1-1/7-1/289-1/85)/4.(1-1/7-1/289-1/85:5.(1+1/13+1/169+1/91)/6.(1+1/13+1/169+1/91).158158158/711711711

  =81.(12/4:5/6).158.1001001/711.1001001

=81.18/5.158/711

=324/5

Ta có \(81.\left(\frac{12-\frac{12}{7}-\frac{12}{289}-\frac{12}{85}}{4-\frac{4}{7}-\frac{4}{289}-\frac{3}{85}}:\frac{5+\frac{5}{13}+\frac{5}{169}+\frac{5}{91}}{6+\frac{6}{13}+\frac{6}{169}+\frac{6}{91}}\right)\)

\(=81.\left(\frac{12.\left(1-\frac{1}{7}-\frac{1}{289}-\frac{1}{85}\right)}{4.\left(1-\frac{1}{7}-\frac{1}{289}-\frac{1}{85}\right)}:\frac{5.\left(1+\frac{1}{13}+\frac{1}{169}+\frac{1}{91}\right)}{6.\left(1+\frac{1}{13}+\frac{1}{169}+\frac{1}{91}\right)}\right)\)

\(=81.\left(\frac{12}{4}:\frac{5}{6}\right)\)

\(=81.\frac{18}{5}\)

\(=291,6\)

\(81\left(\frac{12-\frac{12}{7}-\frac{12}{289}-\frac{12}{85}}{4-\frac{4}{7}-\frac{4}{289}-\frac{4}{85}}:\frac{5+\frac{5}{13}+\frac{5}{169}+\frac{5}{91}}{6+\frac{6}{13}+\frac{6}{159}+\frac{6}{91}}\right)\)

\(=81\left(\frac{12\left(1-\frac{1}{7}-\frac{1}{289}-\frac{1}{85}\right)}{4\left(1-\frac{1}{7}-\frac{1}{289}-\frac{1}{85}\right)}:\frac{5\left(1+\frac{1}{13}+\frac{1}{169}+\frac{1}{91}\right)}{6\left(1+\frac{1}{13}+\frac{2}{169}+\frac{1}{91}\right)}\right)\)

\(=81\left(3\div\frac{5}{6}\right)\)

\(=81.\frac{18}{5}\)

\(=\frac{1458}{5}\)

81.[12(1-1/7-1/289-1/85)/4(1-1/7-1/289-1/85):5(1+1/13+1/169+1/91)/6(1/13+1/169+1/91)

=81.[12/4:5/6]=81.[12/4.6/5]=81.18/5=1458/5

Đổi 91 tấn = 91 000 kg 

91 tấn 6 kg = 91 000 + 6 = 91 006 ( kg )

Đổi 91 006 kg = 916,06 ( tạ )

Đáp số : 916,06 tạ

91 tấn 6 kg=910,06 ta

**** mik nhanh

Thank you every one

..........

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Đổi 91 tấn = 91 000 kg 

91 tấn 6 kg = 91 000 + 6 = 91 006 ( kg )

Đổi 91 006 kg = 916,06 ( tạ )

Đáp số : 916,06 tạ

Ta có:

\(\dfrac{-5}{6}\times\dfrac{52}{52}=\dfrac{-260}{312}\)

\(\dfrac{-91}{104}\times\dfrac{3}{3}=\dfrac{-273}{312}\)

Vì -260>-273⇒\(\dfrac{-260}{312}>\dfrac{-273}{312}\Rightarrow\dfrac{-5}{6}>\dfrac{-91}{104}\)

Vậy:\(\dfrac{-5}{6}>\dfrac{-91}{104}\)

\(-\dfrac{5}{6}=-\dfrac{5.104}{6.104}=-\dfrac{520}{624};-\dfrac{91}{104}=-\dfrac{91.6}{104.6}=-\dfrac{546}{624}\Rightarrow-\dfrac{5}{6}>-\dfrac{91}{104}\)

Ta có:

 \(\dfrac{-91}{104}\) rút gọn cho 13 được \(\dfrac{-7}{8}\)

→ \(\dfrac{-5}{6}=\dfrac{-5.4}{6.4}=\dfrac{-20}{24}\)

\(\dfrac{-7}{8}=\dfrac{-7.3}{8.3}=\dfrac{-21}{24}\)

Vì 20 < 21

nên \(\dfrac{-20}{24}>\dfrac{-21}{24}\) 

hay \(\dfrac{-5}{6}>\dfrac{-91}{104}\)

Chúc bạn học tốt

a: -91/104=-7/8=-21/24

-5/6=-20/24

=>-91/104<-5/6

b: -15/21=-5/7

-36/44=-9/11

5/7=1-2/7; 9/11=1-2/11

mà 2/7>2/11

nên 5/7<9/11

=>-15/21>-36/44