5/6 : 3/13 = 5/6 x 3/13

               = 15/78

\(\frac{5}{6}:\frac{3}{13}=\frac{5}{6}\cdot\frac{13}{3}=\frac{65}{18}\)

\(\frac{5}{6}:\frac{3}{13}=\frac{5}{6}x\frac{3}{13}=\frac{15}{78}\)

Mình rút gọn luôn đó

\(\left(\frac{1}{4}+\frac{3}{8}\right)\times\frac{8}{7}\)

\(=\frac{5}{8}\times\frac{8}{7}\)

\(=\frac{5}{7}\)

#H

\(\left(\frac{1}{4}+\frac{3}{8}\right)\cdot\frac{8}{7}=\frac{5}{8}\cdot\frac{8}{7}=\frac{5}{7}\)

1/4 + 3/8 x 8/7

= ( 1/4 x 3/8 ) x 8/7

=         5/8      x 8/7 

= 40/56 .

#Songminhtử

a, x-2/5=3/8 suy ra x-2.8=3.5 tương đương x-2.8=15 tương đương x-2=1,875 suy ra x=3,875

a)\(\frac{x-2}{5}=\frac{3}{8}\)

\(\Leftrightarrow\)\(x-2=\frac{3}{8}\cdot5\)

\(\Leftrightarrow\)\(x-2=\frac{15}{8}\)

\(\Leftrightarrow x=\frac{31}{8}\)

Vậy x=\(\frac{31}{8}\)

\(\frac{1}{2}=\frac{6}{12}\)\(;\)\(\frac{3}{4}=\frac{9}{12}\)\(;\)\(\frac{5}{6}=\frac{10}{12}\)

\(1000:\frac{3}{4}=\frac{4000}{3}=1333,3333333....\)

1000 : 3/4 = 750 

1000:\(\frac{3}{4}\)

=1000.\(\frac{4}{3}\)

=\(\frac{1000.4}{3}\)

=\(\frac{4000}{3}\)

\(\frac{3}{4}

3/4 < 1 vì có tử số bé hơn mẫu số                             

\(\frac{3}{4}\)< 1 vì 1 = \(\frac{4}{4}\)cho nên \(\frac{3}{4}\)< \(\frac{4}{4}\)