a,-15/21=-5/7

   -55/77=-5/7

\(\frac{-15}{21}=\frac{-15\div3}{21\div3}=\frac{-5}{7}\)

\(\frac{-55}{77}=\frac{-55\div11}{77\div11}=\frac{-5}{7}\)

Vì \(\frac{-5}{7}=\frac{-5}{7}\Rightarrow\frac{-15}{21}=\frac{-55}{77}\)

b , \(\frac{-3737}{5151}=\frac{-3737\div101}{5151\div101}=\frac{-37}{51}\)

\(\frac{-373737}{515151}=\frac{-373737\div10101}{515151\div10101}=\frac{-37}{51}\)

Vì \(\frac{-37}{51}=\frac{-37}{51}\Rightarrow\frac{-3737}{5151}=\frac{-373737}{515151}\)

a: \(\dfrac{20}{30}=\dfrac{2}{3}\)

\(\dfrac{30}{45}=\dfrac{2}{3}\)

Do đó: \(\dfrac{20}{30}=\dfrac{30}{45}\)

b: \(\dfrac{-25}{35}=\dfrac{-5}{7}\)

\(\dfrac{-55}{77}=\dfrac{-5}{7}\)

Do đó: \(-\dfrac{25}{35}=-\dfrac{55}{77}\)

a,20/30=2/3

30/45=2/3

->20/30=30/45

b -25/35=-5/7

-55/77=-5/7

-> -25/35=-55/77

a) Phân số tối giản đều bằng 2/3

b) Phân số tối giản đều bằng -5/7

a: 20/30=2/3

30/45=2/3

=>20/30=30/45

b: -25/35=-5/7

-55/77=-5/7

=>-25/35=-55/77

a,\(-\frac{15}{21}=-\frac{5}{7};-\frac{55}{77}=-\frac{5}{7}\Rightarrow-\frac{15}{21}=-\frac{55}{77}\)

b, \(-\frac{3737}{5151}=-\frac{37}{51};-\frac{373737}{515151}=-\frac{37}{51}\Rightarrow-\frac{3737}{5151}=-\frac{373737}{515151}\)

\(a,\dfrac{20}{30}=\dfrac{30}{45}v\text{ì}20.45=30.30=900\\ b,\dfrac{-25}{35}=\dfrac{-55}{77}v\text{ì}:\left(-25\right).77=35.\left(-55\right)=-1925\)

a) -22/55 = -2/5 ; -26/65 = -2/5

=> -22/55 = -26/65 (= -2/5)

b) 114/122 = 57/61 ; 5757/6161 = 57/61

=> 114/122 = 5757/6161 (=57/61)

a) Ta có : -22/55 = -2/5 

               -26/65 = -2/5

=> -22/55 = -26/65

b) Ta có : 114/122 = 57/61

               5757/6161 = 57/61

=> 114/122 = 5757/6161

Hok tốt !

a)5/3;99/100;29/14

b)9/21;45/105;33/77

\(a.\dfrac{5}{3};\dfrac{99}{100};\dfrac{29}{14}\)

\(b.\dfrac{9}{21};\dfrac{33}{77};\dfrac{45}{105}\)

a) 5/3; 99/100; 29/14

b) 9/21; 33/77; 45/105;