câu a) 3/5 < 4/5

câu b)12/13 < 13/13

 nhé bạn 

a. 3/5 < 4/5

b. 12/13 < 13/13

3/5 be hon 4/5

12/13be hon 13/13

\(a,3\frac{7}{9}=\frac{3\cdot9+7}{9}=\frac{34}{9}\)

\(12\frac{9}{11}=\frac{12\cdot11+9}{11}=\frac{141}{11}\)

\(6\frac{2}{7}=\frac{6\cdot7+2}{7}=\frac{44}{7}\)

\(b,14\frac{1}{8}=\frac{14\cdot8+1}{8}=\frac{113}{8}\)

\(124\frac{4}{35}=\frac{124\cdot35+4}{35}=\frac{4344}{35}\)

a)\(\frac{16}{20}=\frac{4}{5};\frac{9}{15}=\frac{3}{5}\)

Vì 4>3\(\Rightarrow\frac{4}{5}>\frac{3}{5}\) hay \(\frac{16}{20}>\frac{9}{15}\)

Vậy \(\frac{16}{20}>\frac{9}{15}\)

b) \(\frac{6}{8}=\frac{3}{4};\frac{3}{12}=\frac{1}{4}\)

Vì 3>1 \(\Rightarrow\frac{3}{4}>\frac{1}{4}\) hay \(\frac{6}{8}=\frac{3}{12}\)

Vậy \(\frac{6}{8}=\frac{3}{12}\)

c) \(\frac{15}{25}=\frac{3}{5};\frac{36}{45}=\frac{4}{5}\)

Vì 3<4 \(\Rightarrow\frac{3}{5}<\frac{4}{5}\) hay \(\frac{15}{25}<\frac{36}{45}\)

Vậy \(\frac{15}{25}<\frac{36}{45}\)

Neu ban nao dung thi minh tich cho nhe

_{minh khong biet dap an cua cau hoi nay} 

a) Ta có:

+) \(\dfrac{1}{2}=\dfrac{3}{6}\)

+) \(\dfrac{1}{3}=\dfrac{2}{6}\)

+) \(\dfrac{2}{3}=\dfrac{4}{6}\)

=> \(\dfrac{2}{6}< \dfrac{3}{6}< \dfrac{4}{6}\)

hay \(\dfrac{1}{3}< \dfrac{1}{2}< \dfrac{2}{3}\)

b) Ta có:

+) \(\dfrac{4}{9}=\dfrac{56}{126}\)

+) \(-\dfrac{1}{2}=-\dfrac{63}{126}\)

+) \(\dfrac{3}{7}=\dfrac{54}{126}\)

=> \(-\dfrac{63}{126}< \dfrac{54}{126}< \dfrac{56}{126}\)

hay \(-\dfrac{1}{2}< \dfrac{3}{7}< \dfrac{4}{9}\)

c) Ta có:

+) \(\dfrac{27}{82}=\dfrac{2025}{6150}\)

+) \(\dfrac{26}{75}=\dfrac{2132}{6150}\)

=> \(\dfrac{2025}{6150}< \dfrac{2132}{6150}\)

hay \(\dfrac{27}{82}< \dfrac{26}{75}\)

d) Ta có:

+) \(-\dfrac{49}{78}=-\dfrac{4655}{7410}\)

+) \(-\dfrac{64}{95}=-\dfrac{4992}{7410}\)

=> \(-\dfrac{4665}{7410}>-\dfrac{4992}{7410}\)

hay \(-\dfrac{49}{78}>-\dfrac{64}{95}\)

ta có : \(\frac{3}{7}=0,4285....\), 0,(4)=0,4444...

vì 0,4285...<0.4444...

nên \(\frac{3}{7}\)<0,(4)

3/7>0,4 nha bạn

chúc bạn học tốt

3 phan 7 lon hon

a,3/4<4/5

b,7/12>17/36

c,5/6 <6/7 < 7/8

giai thich nua nhe cac bn

a, Ta có : 1 - 3/4 = 1/4 ; 1 - 4/5 = 1/5 

Vì 1/4 > 1/5 nên 3/4 < 4/5

b, Ta có :7/12 = 21/36

Vì 21/36 > 17/36 nên 7/12 > 17/36

c, Ta có:

1 - 5/6 = 1/6

1 - 6/7 = 1/7

1 - 7/8 = 1/8

Vì 1/6 > 1/7 > 1/8 nên 5/6 < 6/7 < 7/8

a, >

b, <

c, <

a, Ta có : 5 < 7 nên \(\frac{1}{5}>\frac{1}{7}\)

b, Ta có : \(\frac{-3}{4}=\frac{\left(-3\right).5}{4.5}=\frac{-15}{20};\frac{2}{5}=\frac{2.4}{5.4}=\frac{8}{20}\)

Vì ( -15 ) < 8 nên \(\frac{-15}{20}< \frac{8}{20}\)hay \(\frac{-3}{4}< \frac{2}{5}\)

c, Ta có : \(\frac{-5}{7}=\frac{\left(-5\right).2}{7.2}=\frac{-10}{14};\frac{-3}{14}=\frac{-3}{14}\)

Vì ( -10 ) < ( -3 ) nên \(\frac{-10}{14}< \frac{-3}{14}\)hay \(\frac{-5}{7}< \frac{-3}{14}\)