\(\frac{5}{6}\times\frac{7}{12}+\frac{5}{12}\times\frac{5}{6}+\frac{1}{6}\) 

= \(\frac{35}{72}+\frac{25}{36}+\frac{1}{6}\)

= \(\frac{97}{72}\)

\(\left(\frac{8}{15}\times\frac{3}{4}\times\frac{5}{4}\right):\frac{7}{8}\)

= \(\frac{1}{2}:\frac{7}{8}\)

=\(\frac{4}{7}\)

HOK TỐT ^^

thank you bn

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

\(\frac{4}{5}\cdot\frac{2}{3}=\frac{8}{15}\)

Vậy : \(\frac{2}{3}:\frac{5}{6}< \frac{4}{5}x\cdot\frac{2}{3}\)nên \(\frac{4}{5}< \frac{8}{15}\)

Mình làm câu A

\(\frac{1}{2}\cdot\frac{3}{4}=\frac{3}{8}\)\(;\frac{5}{8}:\frac{6}{8}=\frac{5}{6}\)

Vậy \(\frac{1}{2}\cdot\frac{3}{4}< \frac{5}{8}:\frac{6}{8}\)

Nên : \(\frac{3}{8}< \frac{5}{6}\)

\(\frac{4}{5}+\frac{1}{6}-\frac{4}{9}=\frac{29}{30}-\frac{4}{9}=\frac{87}{90}-\frac{40}{90}=\frac{11}{30}\)

\(\frac{2}{3}-\frac{1}{4}=\frac{8}{12}-\frac{3}{12}=\frac{5}{12}\)

\(\frac{5}{12}=\frac{150}{360};\frac{11}{30}=\frac{132}{360}\)

\(x=\frac{19}{360}\)

Bài 1 :

\(a)x=\frac{7}{25}+\left(-\frac{1}{5}\right)\)

    \(x=\frac{2}{25}\)

\(b)x=\frac{5}{11}+\left(\frac{4}{-9}\right)\)

    \(x=\frac{1}{99}\)

Mấy câu kia dễ tự làm :>

a: \(y\times4\frac{7}{12}=6\frac14\)

=>\(y\times\frac{55}{12}=\frac{25}{4}\)

=>\(y=\frac{25}{4}:\frac{55}{12}=\frac{25}{4}\times\frac{12}{55}=\frac{3\times5}{11}=\frac{15}{11}\)

b: \(y:3\frac78=5\frac12\)

=>\(y:\frac{31}{8}=\frac{11}{2}\)

=>\(y=\frac{11}{2}\times\frac{31}{8}=\frac{341}{16}\)

c: \(6\frac17:y=5\frac25\)

=>\(\frac{43}{7}:y=\frac{27}{5}\)

=>\(y=\frac{43}{7}:\frac{27}{5}=\frac{43}{7}\times\frac{5}{27}=\frac{215}{189}\)