\(\frac{9}{18}\times\frac{5}{6}+\frac{2}{9}\times\frac{15}{12}\)

=\(\frac{1}{2}\times\frac{5}{6}+\frac{2}{9}\times\frac{5}{4}\)

=\(\frac{5}{12}+\frac{10}{36}\)

=\(\frac{15}{36}+\frac{10}{36}\)

=\(\frac{25}{36}\)

nhớ tk nha bạn

=25/36

\(a.\left(\frac{6}{11}+\frac{5}{11}\right).\frac{3}{7}=1\cdot\frac{3}{7}=\frac{3}{7}b.\frac{3}{5}\cdot\frac{7}{9}+\frac{3}{5}\cdot\frac{2}{9}=\frac{3}{5}\cdot\left(\frac{7}{9}+\frac{2}{9}\right)=\frac{3}{5}\cdot1=\frac{3}{5}\)

\(x+\frac{2}{3}=\frac{9}{11}\)

\(x=\frac{9}{11}-\frac{2}{3}\)

\(x=\frac{5}{33}\)

\(x-\frac{3}{10}=\frac{4}{15}\)

\(x=\frac{3}{10}-\frac{4}{15}\)

\(x=\frac{1}{10}\)

\(x\times\frac{1}{7}=\frac{5}{6}\)

\(x=\frac{5}{6}:\frac{1}{7}\)

\(x=\frac{35}{6}\)

\(x:\frac{3}{5}=\frac{1}{6}\)

\(x=\frac{3}{5}.\frac{1}{6}\)

\(x=\frac{1}{10}\)

+, \(x+\frac{2}{3}=\frac{9}{11}\)

\(x=\frac{9}{11}-\frac{2}{3}=\frac{5}{33}\)

+, \(x-\frac{3}{10}=\frac{4}{15}\)

\(x=\frac{4}{15}+\frac{3}{10}=\frac{17}{30}\)

+, \(x\cdot\frac{1}{7}=\frac{5}{6}\)

\(x=\frac{5}{6}:\frac{1}{7}=\frac{5}{6}.\frac{7}{1}=\frac{35}{6}\)

+,\(x:\frac{3}{5}=\frac{1}{6}\)

\(x=\frac{1}{6}\cdot\frac{3}{5}=\frac{3}{30}=\frac{1}{10}\)

a)\(\dfrac{5}{7}+\dfrac{4}{9}=\dfrac{45}{63}+\dfrac{28}{63}=\dfrac{73}{63}\) ; \(\dfrac{9}{11}+\dfrac{3}{8}=\dfrac{72}{88}+\dfrac{33}{88}=\dfrac{105}{88}\)

\(\dfrac{4}{5}-\dfrac{2}{3}=\dfrac{12}{15}-\dfrac{10}{15}=\dfrac{2}{15}\); \(\dfrac{16}{25}-\dfrac{2}{5}=\dfrac{16}{25}-\dfrac{10}{25}=\dfrac{6}{25}\)

b)\(5+\dfrac{3}{5}=\dfrac{25}{5}+\dfrac{3}{5}=\dfrac{28}{5};10-\dfrac{9}{16}=\dfrac{160}{16}-\dfrac{9}{16}=\dfrac{151}{16}\)

\(\dfrac{2}{3}-\left(\dfrac{1}{6}+\dfrac{1}{8}\right)=\dfrac{2}{3}-\left(\dfrac{8}{48}+\dfrac{6}{48}\right)=\dfrac{2}{3}-\dfrac{14}{48}=\dfrac{32}{48}-\dfrac{14}{48}=\dfrac{3}{8}\)

1) \(\frac{4}{5}.\frac{8}{3}.\frac{x}{7}=\frac{96}{105}\)

\(\frac{32.x}{105}=\frac{96}{105}\)

\(32x=96\)

\(x=3\)

Bài 1: Tìm \(x\)

\(\frac45\times\frac83\times\) \(\frac{x}{7}\) = \(\frac{96}{105}\)

\(\frac{32}{15}\) x \(\frac{x}{7}\) = \(\frac{32}{35}\)

\(\frac{x}{7}\) = \(\frac{32}{35}\) : \(\frac{32}{15}\)

\(\frac{x}{7}\) = \(\frac{32}{35}\) x \(\frac{15}{32}\)

\(\frac{x}{7}\) = \(\frac37\)

\(x=\frac37\times7\)

\(x=3\)

b; \(\frac74\times\frac{3}{x}\times\) \(\frac{11}{5}\) = \(\frac{231}{200}\)

\(\frac74\) x \(\frac{3}{x}\) = \(\frac{231}{200}\) : \(\frac{11}{5}\)

\(\frac74\times\frac{3}{x}\) = \(\frac{231}{200}\) x \(\frac{5}{11}\)

\(\frac74\) x \(\frac{3}{x}\) = \(\frac{21}{40}\)

\(\frac{3}{x}\) = \(\frac{21}{40}\) : \(\frac74\)

\(\frac{3}{x}\) = \(\frac{21}{40}\) x \(\frac47\)

\(\frac{3}{x}\) = \(\frac{3}{10}\)

\(x=3:\frac{3}{10}\)

\(x=3\times\frac{3}{10}\)

\(x=10\)

nhiều quá bạn ơi

12/14 + 15/20 + 6/7 + 3/4 

= ( 12/14 + 6/7 ) + ( 15/20 + 3/4 ) 

= ( 6/7 + 6/7 ) + ( 3/4 + 3/4 ) 

=      12/7 + 6/4 

=      48/28 + 42/28 

=         90/28 

=        45/14

Tham khảo nha !!! 

\(7:\frac{1}{5}=7\cdot\frac{5}{1}=35\)

\(\frac{5}{12}-\frac{5}{15}=\frac{5\cdot15-5\cdot12}{12\cdot15}=\frac{1}{12}\)

\(\frac{7}{9}:\frac{5}{12}=\frac{7}{9}\cdot\frac{12}{5}=\frac{28}{15}\)

\(7:\frac{1}{5}=35\)

\(\frac{5}{12}-\frac{5}{15}=\frac{1}{12}\)

\(\frac{7}{9}:\frac{5}{12}=1\frac{13}{15}=\frac{28}{15}\)

bằng  4/5 nha bạn

\(\frac{4}{5}\div\frac{9}{15}\times\frac{3}{5}\)

\(=\frac{4}{5}\times\frac{15}{9}\times\frac{3}{5}\)

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

k mk nha