Ai trả lời đc mình sẽ 👍 nha 

a. 9/7 < 11/13

b. 12/17 > 5/36

Mik trả lời nek, bn nhớ 👍 nha.
a) 9/7 > 1        ;          11/13 <1
Nên 9/7 > 11/13
b) 12/17=432/612 ;      5/36=85/612
mà 432/612>85/612
12/17>5/36

a. 9/7 < 11/13

b. 12/17 > 5/36

\(\dfrac{12}{17}>\dfrac{1}{2};\dfrac{5}{36}< \dfrac{1}{2}\\ \Rightarrow\dfrac{12}{17}>\dfrac{5}{36}\)

\(\dfrac{12}{17}\) \(>\) \(\dfrac{5}{36}\)

Ai trả lời đc mình sẽ 👍 nha

\(a.\)

\(\dfrac{9}{7}=\dfrac{7+2}{7}=1+\dfrac{2}{7}\)

\(\dfrac{11}{13}=\dfrac{13-2}{13}=1-\dfrac{2}{13}\)

Ta có : \(\dfrac{2}{7}>\dfrac{-2}{13}\)

\(\Rightarrow\dfrac{9}{7}>\dfrac{11}{13}\)

a) Ta có : a + 1 > a - 1

=> \(\frac{1}{a+1}\) < \(\frac{1}{a-1}\)

a) \(\frac{1}{a+1}< \frac{1}{a}< \frac{1}{a-1}\Rightarrow\frac{1}{a+1}< \frac{1}{a-1}\)

b) \(\frac{23}{47}< \frac{23}{45}< \frac{24}{45}\Rightarrow\frac{23}{47}< \frac{24}{45}\)

c) \(\frac{12}{17}>\frac{1}{2}>\frac{7}{15}\Rightarrow\frac{12}{17}>\frac{7}{15}\)

d) \(\frac{34}{43}< \frac{35}{43}< \frac{35}{42}\Rightarrow\frac{34}{43}< \frac{35}{42}\)

Cảm ơn các bạn rất nhiều

hello

Ta có:\(\frac{12}{17}>\frac{12}{24}=\frac{1}{2}=\frac{7}{14}>\frac{7}{15}\)

Vậy \(\frac{12}{17}>\frac{7}{15}\)

Hoặc bạn quy đồng