Có \(\frac{4}{9}< 1\)VÀ \(\frac{8}{7}>1\)
\(\Rightarrow\frac{4}{9}< \frac{8}{7}\)
đơn giản :
\(\frac{4}{9}< 1\)
\(\frac{8}{7}>1\)
\(\Rightarrow\frac{4}{9}< 1< \frac{8}{7}\)
\(\frac{4}{9}=\frac{28}{63}\) \(\frac{8}{7}=\frac{72}{63}\)
Vì \(\frac{28}{63}< \frac{72}{63}\)nên \(\frac{4}{9}< \frac{8}{7}\)
\(\frac{4}{9}=\frac{28}{63}\); \(\frac{8}{7}=\frac{72}{63}\)
\(\frac{28}{63}< \frac{72}{63}=>\frac{4}{9}< \frac{8}{7}\)
\(\frac{4}{9}=\frac{28}{63};\frac{8}{7}=\frac{72}{63}\)
Vì \(\frac{28}{63}< \frac{72}{63}\)nên => \(\frac{4}{9}< \frac{8}{7}\)
Quy đồng mẫu số:
\(\frac{4}{9}=\frac{4.7}{9.7}=\frac{28}{63};\frac{8}{7}=\frac{8.9}{7.9}=\frac{72}{63}\)
Vì \(\frac{28}{63}< \frac{72}{63}\)
\(\Rightarrow\frac{4}{9}< \frac{8}{7}\)