\(\dfrac{15}{35}=\dfrac{15:5}{35:5}=\dfrac{3}{7}\)

\(\dfrac{24}{27}=\dfrac{24:3}{27:3}=\dfrac{8}{9}\)

\(\dfrac{17}{50}\) ( phân số dã tối giản )

\(\dfrac{15}{45}=\dfrac{15:3}{45:3}=\dfrac{5}{15}=\dfrac{5:5}{15:5}=\dfrac{1}{3}\)

\(\dfrac{99}{121}=\dfrac{99:11}{121:11}=\dfrac{9}{11}\)

`15/35 = (15 \div 5)/(35 \div 5)=3/7`

`24/27 = (24 \div 3)/(27 \div 3)=8/9`

`17/50` đã rút gọn

`15/45=(15 \div 15)/(45 \div 15)=1/3`

`99/121=(99 \div 11)/(121 \div 11)=9/11`

a: Phân số tối giản là 25/27; 77/79

b: 51/34=3/2

77/99=7/9

120/201=40/67

351/621=13/23

21/15=21:3/15:3=7/5

11/121=11:11/121:11=1/11

27/72=27:9/72:9=3/8

\(\dfrac{21}{15}=\dfrac{7}{5};\dfrac{11}{121}=\dfrac{1}{11};\dfrac{27}{72}=\dfrac{3}{8}\)

\(\dfrac{21}{15}=\dfrac{21:3}{15:3}=\dfrac{7}{5}\)

\(\dfrac{11}{121}=\dfrac{11:11}{121:11}=\dfrac{1}{11}\)

\(\dfrac{27}{72}=\dfrac{27:9}{72:9}=\dfrac{3}{8}\)

11/6

\(\dfrac{11}{6}\)

`121/66=[121:11]/[66:11]=11/6`

Phân số trên đã là phân số tối giản rồi 

Phân số trên đã là phân số tối giản rồi 

\(\dfrac{12}{18}=\dfrac{12:6}{18:6}=\dfrac{2}{3}\)

\(\dfrac{49}{21}=\dfrac{49:7}{21:7}=\dfrac{7}{3}\)

\(\dfrac{15}{35}=\dfrac{15:5}{35:5}=\dfrac{3}{7}\)

\(\dfrac{26}{34}=\dfrac{26:2}{34:2}=\dfrac{13}{17}\)

\(\dfrac{11}{121}=\dfrac{11:11}{121:11}=\dfrac{1}{11}\)

\(\dfrac{12}{18}=\dfrac{12:6}{18:6}=\dfrac{2}{3};\dfrac{49}{21}=\dfrac{49:7}{21:7}=\dfrac{7}{3};\dfrac{15}{35}=\dfrac{15:5}{35:5}=\dfrac{3}{7};\dfrac{26}{34}=\dfrac{26:2}{34:2}=\dfrac{13}{17};\dfrac{11}{121}=\dfrac{11:11}{121:11}=\dfrac{1}{11}\)

2/3
7/3
5/7
13/17
1/11

121/143=11/13

1212/1414=6/7

123123/456456=123/456=41/152

\(\dfrac{121}{143}=\dfrac{11}{13}\) ;  \(\dfrac{1212}{1414}=\dfrac{6}{7}\) ;  \(\dfrac{123}{456}=\dfrac{41}{152}\)

121/143 = 11/13

1 212 / 1414 = 6/7

123 123/456 456 = 123/456 = 41/152