Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
A =\(\frac{2}{5}\times\frac{4}{7}+\frac{3}{5}\times\frac{4}{7}\) B = \(\frac{17}{13}\times\frac{12}{17}-\frac{4}{13}\times\frac{12}{17}\) C = \(\frac{9}{14}:\frac{6}{7}+\frac{5}{14}:\frac{6}{7}\) D =\(\frac{9}{12}:\frac{7}{9}\times\frac{12}{19}\)
= \(\frac{4}{7}\times\left(\frac{2}{5}+\frac{3}{5}\right)\) =\(\left(\frac{17}{13}-\frac{4}{13}\right)\times\frac{12}{17}\) = \((\frac{9}{14}+\frac{5}{14}):\frac{6}{7}\) = \(\frac{9}{12}\times\frac{9}{7}\times\frac{12}{19}\)
=\(\frac{4}{7}\times1\) = \(1\times\frac{12}{17}\) = \(1:\frac{6}{7}\) = \(\frac{9\times9\times12}{12\times7\times19}\)
=\(\frac{4}{7}\) = \(\frac{12}{17}\) =\(\frac{7}{6}\) = \(\frac{9\times9}{7\times19}=\frac{81}{133}\)
\(\frac{2}{5}+\frac{7}{12}+\frac{13}{12}=\frac{31}{15}\)
k mình nha các bạn . chúc các bạn học giỏi
\(\dfrac{11}{12}\times\dfrac{12}{13}\times\dfrac{13}{14}:\dfrac{22}{28}\)
\(=\dfrac{11}{12}\times\dfrac{12}{13}\times\dfrac{13}{14}\times\dfrac{14}{11}\)
\(=\dfrac{11\times12\times13\times14}{12\times13\times14\times11}\)
\(=1\)
=================
\(3\times\dfrac{7}{10}+\dfrac{7}{10}\times5+2\times\dfrac{7}{10}\)
\(=\dfrac{7}{10}\times\left(3+5+2\right)\)
\(=\dfrac{7}{10}\times10=7\)
\(\dfrac{11}{12}\times\dfrac{12}{13}\times\dfrac{13}{14}:\dfrac{22}{28}\)
\(=\dfrac{11}{12}\times\dfrac{12}{13}\times\dfrac{13}{14}:\dfrac{11}{14}\)
\(=\dfrac{11}{12}\times\dfrac{12}{13}\times\dfrac{13}{14}\times\dfrac{14}{11}\)
\(=\dfrac{11\times12\times13\times14}{12\times13\times11\times14}\)
\(=1\)
\(3\times\dfrac{7}{10}+\dfrac{7}{10}\times5+2\times\dfrac{7}{10}\)
\(=\dfrac{7}{10}\times\left(3+5+2\right)\)
\(=\dfrac{7}{10}\times10\)
\(=7\)
\(\dfrac{7}{5}+\dfrac{8}{5}+\dfrac{7}{2}+\dfrac{1}{2}+\dfrac{12}{13}+\dfrac{27}{13}=\dfrac{15}{5}+\dfrac{8}{2}+\dfrac{39}{13}=3+4+3=10\)
\(\dfrac{7}{6}\) + \(\dfrac{5}{12}\) - \(\dfrac{1}{18}\) - 1
= \(\dfrac{42}{36}\) + \(\dfrac{15}{36}\) - \(\dfrac{2}{36}\) - \(\dfrac{36}{36}\)
= \(\dfrac{19}{36}\)
\(\dfrac{13}{6}\) + \(\dfrac{5}{18}+3-\dfrac{7}{12}\)
= \(\dfrac{78}{36}+\dfrac{10}{36}+\dfrac{108}{36}-\dfrac{21}{36}\)
= \(\dfrac{175}{36}\)
3 + \(\dfrac{11}{4}-\dfrac{1}{12}-\dfrac{3}{16}\)
= \(\dfrac{144}{48}+\dfrac{132}{48}-\dfrac{4}{48}-\dfrac{9}{48}\)
= \(\dfrac{263}{48}\)
\(\dfrac{2}{5}\) x \(\dfrac{7}{4}\) - \(\dfrac{2}{5}\) x \(\dfrac{3}{4}\)
= \(\dfrac{2}{5}\) x ( \(\dfrac{7}{4}\) - \(\dfrac{3}{4}\))
= \(\dfrac{2}{5}\) x \(\dfrac{4}{4}\)
= \(\dfrac{2}{5}\)
\(\dfrac{12}{13}+\dfrac{2}{7}+\dfrac{8}{13}+\dfrac{6}{13}+\dfrac{5}{7}\)
\(=\left(\dfrac{12}{13}+\dfrac{8}{13}+\dfrac{6}{13}\right)+\left(\dfrac{2}{7}+\dfrac{5}{7}\right)\)
\(=2+1\)
\(=3\)
= ( 12/13 + 8/13 + 6/13 ) + ( 2/7 + 5/7 )
= 26/13 + 7/7
= 2 + 1
= 3
a. \(\left(2-\frac{2}{17}\right)\times\frac{51}{64}\)
\(=\frac{22}{17}\times\frac{51}{64}\)
\(=\frac{22\times51}{17\times64}=\frac{1122}{1088}=\frac{561}{544}\)
b. \(\left(\frac{2}{5}+\frac{5}{7}\right)\times\frac{5}{13}\)
\(=\frac{39}{35}\times\frac{5}{13}\)
\(=\frac{3}{7}\)
c. \(\frac{13}{18}\div\left(\frac{7}{12}-\frac{4}{9}\right)\)
\(=\frac{13}{18}\div\frac{28}{27}\)
\(=\frac{13}{18}\times\frac{27}{28}=\frac{39}{56}\)
#z
\(\left(2-\frac{2}{17}\right)\times\frac{51}{64}\)
\(=\frac{32}{17}\times\frac{51}{64}\)
\(=\frac{1632}{1088}=\frac{3}{2}\)
\(\left(\frac{2}{5}+\frac{5}{7}\right)\times\frac{5}{13}\)
\(=\left(\frac{14}{35}+\frac{25}{35}\right)\times\frac{5}{13}\)
\(=\frac{39}{35}\times\frac{5}{13}\)
\(=\frac{195}{455}=\frac{3}{7}\)
\(\frac{13}{18}:\left(\frac{7}{12}-\frac{4}{9}\right)\)
\(=\frac{13}{18}:\left(\frac{63}{108}-\frac{48}{108}\right)\)
\(=\frac{13}{18}:\frac{5}{36}\)
\(=\frac{13}{18}\times\frac{36}{5}\)
\(=\frac{468}{90}=\frac{26}{5}\)