`= (2 . ( 1 - 1/19 + 1/195 - 1/1954))/(3 . (1 - 1/19 + 1/195 - 1/1954))`
`= 2/3`
( Hnhu tớ có gặp cậu ở đâu rồi đấy ạ. )
Đúng 2
Bình luận (3)
Đại số lớp 7
Các câu hỏi tương tự
1, So sánh A và B biết Adfrac{2^{19}.27^3+15.4^9.9^4}{6^9.2^{10}+12^{10}} Bdfrac{4}{35}+dfrac{4}{63}+dfrac{4}{99}+dfrac{4}{143}+dfrac{4}{195}...
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1, So sánh A và B biết A=\(\dfrac{2^{19}.27^3+15.4^9.9^4}{6^9.2^{10}+12^{10}}\) B=\(\dfrac{4}{35}+\dfrac{4}{63}+\dfrac{4}{99}+\dfrac{4}{143}+\dfrac{4}{195}\) ( GIÚP Mk Với Mk Đang Cần Gấp )
Bài 1:1/left(-dfrac{25}{13}right)+left(-dfrac{19}{17}right)+dfrac{12}{13}+left(-dfrac{25}{17}right) 6/ 2dfrac{2}{15}.dfrac{9}{17}.dfrac{3}{32}:left(-dfrac{3}{17}right)2/dfrac{1}{2}-left(-dfrac{1}{3}right)+dfrac{1}{23}+dfrac{1}{6} 7/left(dfrac{-3}{4}+dfrac{2}{5}right):dfrac{3}{7}+left(dfrac{3}{5}+dfrac{-1}{4}right):dfrac{3}{7}3/left(-dfrac{3}{7}right).dfrac{5}{11}+left(-dfrac{5}{14}right).dfrac{5}{11} ...
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Bài 1:
1/\(\left(-\dfrac{25}{13}\right)+\left(-\dfrac{19}{17}\right)+\dfrac{12}{13}+\left(-\dfrac{25}{17}\right)\) 6/ \(2\dfrac{2}{15}.\dfrac{9}{17}.\dfrac{3}{32}:\left(-\dfrac{3}{17}\right)\)
2/\(\dfrac{1}{2}-\left(-\dfrac{1}{3}\right)+\dfrac{1}{23}+\dfrac{1}{6}\) 7/\(\left(\dfrac{-3}{4}+\dfrac{2}{5}\right):\dfrac{3}{7}+\left(\dfrac{3}{5}+\dfrac{-1}{4}\right):\dfrac{3}{7}\)
3/\(\left(-\dfrac{3}{7}\right).\dfrac{5}{11}+\left(-\dfrac{5}{14}\right).\dfrac{5}{11}\) 8/\(\left(-\dfrac{1}{3}\right).\left(-\dfrac{15}{19}\right).\dfrac{38}{45}\)
4/\(\left(-\dfrac{5}{11}\right).\dfrac{7}{15}.\dfrac{11}{-5}.\left(-30\right)\) 9/\(\dfrac{1}{2.3}+\dfrac{1}{3.4}+\dfrac{1}{4.5}+......+\dfrac{1}{19.20}\)
5/\(\left(-\dfrac{5}{9}\right).\dfrac{3}{11}+\left(-\dfrac{13}{18}\right).\dfrac{3}{11}\) 10/\(\dfrac{1}{9.10}-\dfrac{1}{8.9}-\dfrac{1}{7.8}-......-\dfrac{1}{2.3}-\dfrac{1}{1.2}\)
VT
2 tháng 11 2021 lúc 17:01
Thực hiện phép tính hợp lí (nếu có thể):
A = \(\dfrac{11}{9}.\dfrac{-3}{2}-\dfrac{11}{9}.\dfrac{15}{2}+\left(-2021\right)^0\)
\(\dfrac{x+1}{1}+\dfrac{2x+3}{3}+\dfrac{3x+5}{5}+...+\dfrac{10x+19}{19}=12+\dfrac{4}{3}+\dfrac{6}{5}+...+\dfrac{20}{19}\)
Bài 1: Cho D= \(\dfrac{3}{1^2.2^2}+\dfrac{5}{2^2.3^2}+\dfrac{7}{3^2.4^2}+...+\dfrac{19}{9^2.10^2}\). Chứng minh D < 1
\(\dfrac{5}{3}x-\dfrac{2}{5}x=\dfrac{19}{10}\)
\(\dfrac{45}{19}-\left(\dfrac{1}{2}+\left(\dfrac{1}{3}+\left(\dfrac{1}{4}\right)^{-1}\right)^{-1}\right)^{-1}\)
VT
15 tháng 12 2021 lúc 21:44
Thực hiện phép tính (tính nhanh nếu có thể):
a) \(\left(\dfrac{1}{2}-\dfrac{1}{3}\right)-\left(\dfrac{5}{3}-\dfrac{3}{2}\right)+\left(\dfrac{7}{3}-\dfrac{5}{2}\right)\)
b) \(\left(\dfrac{3}{4}-1\dfrac{1}{6}\right)^2:\sqrt{\dfrac{25}{144}}\)
Tính:
a/dfrac{1+dfrac{1}{2}+dfrac{1}{3}+dfrac{1}{4}}{1-dfrac{1}{2}+dfrac{1}{3}-dfrac{1}{4}}:dfrac{3+dfrac{3}{2}+dfrac{3}{3}+dfrac{3}{4}}{2-dfrac{2}{2}+dfrac{2}{3}-dfrac{2}{4}}
b/dfrac{1+dfrac{1}{4}+dfrac{1}{1+dfrac{1}{4}}}{1-dfrac{1}{4}-dfrac{1}{1-dfrac{1}{4}}}
c/dfrac{dfrac{2}{5}-dfrac{7}{5}}{dfrac{2}{5}-dfrac{dfrac{3}{4}}{dfrac{3}{4}.dfrac{3}{7}-1}}-dfrac{1}{dfrac{3}{7}left(dfrac{3}{4}.dfrac{3}{7}.dfrac{2}{5}-dfrac{2}{5}-dfrac{3}{4}right)}
d/left(dfrac{dfrac{4}{3}}{2+dfrac{4}{3}}+dfrac{2-d...
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Tính:
a/\(\dfrac{1+\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{4}}{1-\dfrac{1}{2}+\dfrac{1}{3}-\dfrac{1}{4}}:\dfrac{3+\dfrac{3}{2}+\dfrac{3}{3}+\dfrac{3}{4}}{2-\dfrac{2}{2}+\dfrac{2}{3}-\dfrac{2}{4}}\)
b/\(\dfrac{1+\dfrac{1}{4}+\dfrac{1}{1+\dfrac{1}{4}}}{1-\dfrac{1}{4}-\dfrac{1}{1-\dfrac{1}{4}}}\)
c/\(\dfrac{\dfrac{2}{5}-\dfrac{7}{5}}{\dfrac{2}{5}-\dfrac{\dfrac{3}{4}}{\dfrac{3}{4}.\dfrac{3}{7}-1}}-\dfrac{1}{\dfrac{3}{7}\left(\dfrac{3}{4}.\dfrac{3}{7}.\dfrac{2}{5}-\dfrac{2}{5}-\dfrac{3}{4}\right)}\)
d/\(\left(\dfrac{\dfrac{4}{3}}{2+\dfrac{4}{3}}+\dfrac{2-\dfrac{4}{3}}{\dfrac{4}{3}}\right).\left(\dfrac{\dfrac{2}{3}}{4+\dfrac{2}{3}}-\dfrac{4-\dfrac{2}{3}}{\dfrac{2}{3}}\right)\)
Giúp mik với các bạn ơi 1 bài thôi cug đc.
Ae giúp tôi với:
Cho A=\(1-\dfrac{2}{3}+\left(\dfrac{2}{3}\right)^2-\left(\dfrac{2}{3}\right)^3+...+\left(\dfrac{2}{3}\right)^{2018}-\left(\dfrac{2}{3}\right)^{2019}\)
Chứng tỏ A không thuộc tập hợp Z( tập hợp số nguyên).
Thank all !