C1: 6/7<1<7/6
C2: 6/7=36/42
7/6=49/42
mà 36<49
nên 6/7<7/6
\(\)Quy đồng lên mẫu chung là 42 ta có
\(36/42<49/42\) nhé
\(c1:\dfrac{6}{7}< 1< \dfrac{7}{6}\\ c2:\dfrac{6}{7}=\dfrac{6\times6}{7\times6}=\dfrac{36}{42}\\ \dfrac{7}{6}=\dfrac{7\times6}{6\times7}=\dfrac{49}{42}\\ \Rightarrow\dfrac{36}{42}< \dfrac{49}{42}\\ \Rightarrow\dfrac{6}{7}< \dfrac{7}{6}\)