So sánh 2 phân số 456 481 và123 128

1.\[\frac{456}{461}va\frac{123}{128}\]

Ta có: \[\frac{456}{461}+\frac{5}{461}=1\]

\[\frac{123}{128}+\frac{5}{128}=1\]

vì \[\frac{5}{461}< \frac{5}{128}\]nên \[\frac{456}{461}>\frac{123}{128}\]

2.\[\frac{53}{57}va\frac{531}{571}\]

Vì \[\frac{53}{57}< 1\]

\[\Rightarrow\frac{53}{57}=\frac{530}{570}< \frac{530+1}{570+1}=\frac{531}{571}\]

\[\Rightarrow\frac{53}{57}< \frac{531}{571}\]