a: =1/2+3/2=2

b: =2/5+7/5=9/5

c: =2/3+2/3=4/3

ai trả lời cho mình vs sos

a) \(\frac{25}{5}\); \(\frac{7}{3}\) ;   \(\frac{25}{35}\); \(\frac{5}{8}\); \(\frac{21}{56}\)

b) \(\frac{9}{2}\) ; \(\frac{9}{7}\);  \(\frac{25}{50}\); \(\frac{2}{9}\); \(\frac{1}{5}\)

k cho mk nha

\(\frac{18}{7}:9=\frac{18}{7}:\frac{9}{1}=\frac{18}{7}×\frac{1}{9}=\frac{9×2×1}{7×9}=\frac{2}{7}\)

\(\frac{64}{35}:4=\frac{64}{35}:\frac{4}{1}=\frac{64}{35}×\frac{1}{4}=\frac{16×4×1}{35×4}=\frac{16}{35}\)

\(\frac{24}{11}:12=\frac{24}{11}:\frac{12}{1}=\frac{24}{11}×\frac{1}{12}=\frac{12×2×1}{11×12}=\frac{2}{11}\)

\(\frac{35}{14}:5=\frac{35}{14}:\frac{5}{1}=\frac{35}{14}×\frac{1}{5}=\frac{5×7×1}{14×5}=\frac{7}{14}=\frac{1}{2}\)

18/17:9=18/17:9/1=18/17x1/9=2/17

64/35:4=64/35:4/1=64/35x1/4=16/35

24/11:12=24/11:12/1=24/11x1/12=2/11

35/4:5=35/4:5/1=35/4x1/5=7/4

=\(\dfrac{1}{6}\)

\(\dfrac{1}{6}\)

Bài 1: 

Các phân số 3/5; 9/20; 17/27 là phân số tối giản

Bài 2: 

a: 1/4=7/28

3/7=12/28

b: 4/5=28/35

17/35=17/35

c: 4/9=28/63

8/21=24/63

d: 5/6=20/24

7/8=21/24

\(a,\frac{2}{3};\frac{25}{35};\frac{6}{7};\frac{8}{3};\frac{27}{5}\)

\(b,\frac{2}{9};\frac{13}{27};\frac{45}{75};\frac{21}{28};\frac{6}{5}\)

~~ học tốt nha ~~~

chịu mình không thể giải được

Mấy con gà lắt nhắt này, dễ thế mà cũng ko tính đc.

\(\dfrac{3}{4}\times\dfrac{5}{7}=\dfrac{15}{28};\dfrac{5}{8}\times\dfrac{4}{15}=\dfrac{20}{120}=\dfrac{1}{6};\dfrac{7}{12}\times\dfrac{4}{9}=\dfrac{28}{108}=\dfrac{7}{27};\)

\(\dfrac{1}{6}\times\dfrac{3}{5}=\dfrac{3}{30}=\dfrac{1}{10};\dfrac{12}{21}\times\dfrac{23}{8}=\dfrac{276}{168}=\dfrac{23}{14};\dfrac{13}{4}\times\dfrac{5}{39}=\dfrac{65}{156}=\dfrac{5}{12}\)

\(\dfrac{7}{42}\times\dfrac{13}{21}=\dfrac{91}{882}=\dfrac{13}{126};\dfrac{3}{16}\times\dfrac{4}{15}=\dfrac{12}{240}=\dfrac{1}{20}\)