Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a,1818:101=18 b,123123:1001=123
2727:101=27 345345:1001=345
18/27=2/3 123/345=41/115
Ta có : \(\frac{1919}{2323}x\frac{464646}{747474}x\frac{37}{19}\)
\(=\frac{19}{23}x\frac{23}{37}x\frac{37}{19}\)
\(=\frac{19x23x37}{23x37x19}\)
\(=1\)
~ Chúc các bn học giỏi và may mắn ~
\(\frac{1919}{2323}.\frac{464646}{747474}.\frac{37}{19}\)
\(=\frac{1919:101}{2323:101}.\frac{464646:10101}{747474:10101}.\frac{37}{19}\)
\(=\frac{19}{23}.\frac{46}{74}.\frac{37}{19}\)
\(=\frac{19.46.37}{23.74.19}=\frac{19.23.2.37}{23.37.2.19}=1\)
Ta có: \(\frac{2}{1.2}+\frac{2}{2.3}+\frac{2}{3.4}+...+\frac{2}{18.19}+\frac{2}{19.20}=2.\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{18.19}+\frac{1}{19.20}\right)\)
\(=2.\left(\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{18}-\frac{1}{19}+\frac{1}{19}-\frac{1}{20}\right)\)
\(=2.\left(1-\frac{1}{20}\right)=\frac{2.19}{20}=\frac{19}{10}\)
\(\frac{2}{1\times2}+\frac{2}{2\times3}+......+\frac{2}{19\times20}\)
\(=2\left(\frac{1}{1\times2}+\frac{1}{2\times3}+.......+\frac{1}{19\times20}\right)\)
\(=2\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+........+\frac{1}{19}-\frac{1}{20}\right)\)
\(=2\left(1-\frac{1}{20}\right)=2.\frac{19}{20}=\frac{19}{10}\)
=\(\frac{2001x2004x1001x2006}{2004x2006x2001x2002}\)=\(\frac{1}{2}\)
\(=\frac{2001.2004.1001.2002}{2004.2006.2001.2002}=\frac{1.1.1001.1}{1.2006.1.1}=\frac{1001}{2006}\)
Đáp án lần lượt là: \(\frac{23}{36};\frac{31}{7};\frac{1}{6};\frac{3}{5}\)
#Hk_tốt
#Ken'z
\(\frac{123123}{345345}-\frac{808}{2323}+\frac{3\times5\times9}{23\times25\times27}\)
\(=\frac{123}{345}-\frac{8}{23}+\frac{3\times5\times9}{23\times5\times5\times3\times9}\)
\(=\frac{123}{345}-\frac{8}{23}+\frac{1}{115}\)
\(=\frac{41}{115}-\frac{40}{115}+\frac{1}{115}\)
\(=\frac{2}{115}\)
\(HT\)
:((((