^{_{\(\dfrac{5}{7}=\dfrac{15}{21};\dfrac{6}{8}=\dfrac{3}{4};\dfrac{8}{9}=\dfrac{16}{18};\dfrac{12}{16}=\dfrac{18}{24}\)}}

\(\dfrac{5}{7}=\dfrac{15}{21};\dfrac{6}{8}=\dfrac{18}{24};\dfrac{8}{9}=\dfrac{16}{18};\dfrac{3}{4}=\dfrac{12}{16}\)

5/7=15/21;6/8=3/4;8/9=16/18;12/16=18/24

a: 5/3=10/6=25/15=35/21

b: 5/7=35/49

6/15=12/30

4/5=16/20

c: 6=216/36=324/54=108/18

a)\(\dfrac{5}{3}=\dfrac{10}{6}=\dfrac{25}{15}=\dfrac{35}{21}\)

b)\(\dfrac{5}{7}=\dfrac{35}{49};\dfrac{6}{15}=\dfrac{12}{30};\dfrac{4}{5}=\dfrac{16}{20}\)

c) \(6=\dfrac{216}{36}=\dfrac{324}{54}=\dfrac{108}{18}\)

Ai giải đc bài này thì mik cảm ơn

Phân số không bằng các phân số còn lại là   7/-30; 15/21

\(\dfrac{105}{135}\)

105/135

105/135=7/9

\(\dfrac{20}{35}\text{=}\dfrac{4}{7}\)

\(\dfrac{5}{15}\text{=}\dfrac{1}{3}\)

\(\dfrac{12}{21}\text{=}\dfrac{4}{7}\)

\(\dfrac{8}{10}\text{=}\dfrac{4}{5}\)

\(\dfrac{20}{30}\text{=}\dfrac{2}{3}\)

\(\Rightarrow\left(\dfrac{20}{35}\text{=}\dfrac{12}{21}\text{=}\dfrac{4}{7}\right);\left(\dfrac{20}{30}\text{=}\dfrac{2}{3}\right).\)

4/7 = 12/21 = 20/35

HT

20/35=12/21=4/7
2/3=20/30
 

4/5=44/55

6/7=30/35=54/63

3/10=21/70=30/100

8/12=14/21

12/6 và 20/8 ko có phân số nào bằng nhau

Đáp án là B nhé 

Đáp án B