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a \(\frac{4}{18}+\frac{5}{13}+\frac{7}{9}+\frac{21}{13}\)

= \(\left(\frac{4}{18}+\frac{7}{9}\right)+\left(\frac{5}{13}+\frac{21}{13}\right)\)

= \(1+2\)

= \(3\)

b \(\frac{4}{3}-\frac{2}{7}-\frac{5}{7}+\frac{2}{3}\)

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

= \(\frac{2}{3}-1\)

= \(-\frac{1}{3}\)

Kết quả của bài 1/5+1/10+1/20+1/40+1/80+1/160 là gì

 \(=\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+...+\frac{1}{10}\)có 9 p/số

\(=\frac{1}{10}.9=\frac{9}{10}\)

= 1/10 + 1/10 + ...................... + 1/10 có 9 phân số

= 1/10 x 9

= 9/10

ai tk mình mình đang bị âm điểm

9 / 12 bn nha

tk mk nha các bn

thanks nhiêu

a, \(\frac{6}{7}.\frac{16}{15}.\frac{7}{6}.\frac{21}{32}=\frac{6}{7}.\frac{7}{6}.\frac{16}{15}.\frac{21}{32}\)=\(1.\frac{16}{15}.\frac{21}{32}=\frac{7}{5.2}=\frac{7}{10}\)

Phần b T²

c,\(\frac{7}{4}.\frac{11}{21}+\frac{11}{21}.\frac{5}{4}=\frac{11}{21}.\left(\frac{7}{4}+\frac{5}{4}\right)\)=\(\frac{11}{21}.3=\frac{11}{7}\)

cảm ơn bạn nha

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

\(\frac{1}{2}:\frac{3}{4}+\frac{1}{6}:\frac{3}{4}=\frac{3}{4}:\left(\frac{1}{2}+\frac{1}{6}\right)=\frac{3}{4}:\frac{2}{3}=\frac{9}{8}\)

\(\frac{2}{3}.\frac{4}{5}-\frac{1}{3}.\frac{4}{5}=\frac{4}{5}\left(\frac{2}{3}-\frac{1}{3}\right)=\frac{4}{5}.\frac{1}{3}=\frac{4}{15}\)

\(\frac{1}{2}:\frac{3}{4}-\frac{1}{6}:\frac{3}{4}=\frac{3}{4}:\left(\frac{1}{2}-\frac{1}{6}\right)=\frac{3}{4}:\frac{1}{3}=\frac{9}{4}\)

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

\(\frac{1}{2}:\frac{3}{4}+\frac{1}{6}:\frac{3}{4}=\frac{1}{2}.\frac{4}{3}+\frac{1}{6}.\frac{4}{3}=\left(\frac{1}{2}+\frac{1}{6}\right).\frac{4}{3}=\frac{2}{3}.\frac{4}{3}=\frac{8}{9}\)

c,d tương tự 

A) \(\frac{2}{3}\). \(\frac{4}{5}\)+ \(\frac{1}{3}\). \(\frac{4}{5}\)    B) \(\frac{1}{2}\). \(\frac{4}{5}\)+ \(\frac{1}{6}\): \(\frac{3}{4}\)      C) \(\frac{2}{3}\). \(\frac{4}{5}\)- \(\frac{1}{3}\). \(\frac{4}{5}\)         

= \(\left(\frac{2+1}{3}\right)\). \(\frac{4}{5}\)                =  \(\frac{2}{5}\)+ \(\frac{2}{9}\)                         = \(\frac{2}{3}\)- \(\frac{1}{3}\). \(\left(\frac{4-4}{5}\right)\)

= 1 . \(\frac{4}{5}\)                                   = \(\frac{28}{45}\)                                   = \(\frac{1}{3}\). 0

= \(\frac{4}{5}\)                                                                                         = 0

\(a)\frac{4^{17}.3^4.9^6}{6^{13}}=\frac{2^{34}.3^4.3^{12}}{2^{13}.3^{13}}=\frac{2^{21}.3^{16}}{3^{13}}=2^{21}.3^3\)

\(b)\frac{2^{16}+2^8}{2^{13}+2^5}=\frac{2^8\left(2^8+1\right)}{2^5\left(2^8+1\right)}=\frac{2^3\left(2^8+1\right)}{2^8+1}=2^3=8\)

\(a,\frac{4^{17}\times3^4\times9^6}{6^{13}}\)

\(=\frac{2^{34}\times3^4\times3^{12}}{2^{13}\times3^{13}}\)

\(=\frac{2^{34}\times3^{16}}{2^{13}\times3^{13}}\)

\(=2^{21}\times3^3\)

\(b,\frac{2^{16}+2^8}{2^{13}+2^5}\)

\(=\frac{2^8\left(2^8+2^0\right)}{2^5\left(2^8+2^0\right)}\)

\(=\frac{2^8}{2^5}\)

\(=8\)

~Study well~

các bạn trả lời giúp mình nhé

a)2 phần 5

b)4 phần 5

\(\frac{2}{3}\times\frac{3}{4}\times\frac{4}{5}=\frac{2}{5}\)

\(\frac{1}{2}:\frac{3}{4}:\frac{5}{6}=\frac{1}{2}\times\frac{4}{3}\times\frac{6}{5}=\frac{1\times2\times2}{5}=\frac{4}{5}\)

\(\frac{2}{3}.\frac{3}{4}.\frac{4}{5}=\frac{2}{5}=\frac{4}{10}=0,4\)

\(\frac{1}{2}:\frac{3}{4}:\frac{5}{6}=\frac{1}{2}.\frac{4}{3}.\frac{6}{5}=\frac{4}{5}=\frac{8}{10}=0,8\)

= 93/4 . 7/5 - 53/4 : 5/7

=93/4 . 7/5 - 53/4 . 7/5

= 7/5 .( 93/4 - 53/4 )

= 7/5 . 10 ( rút gọn chéo 7/5 . 10 = 7 .2 =14)

= 14

tích cho mình nha