b) Ta có:
\(\frac{1234.1235-1}{1234.1235}=1-\frac{1}{1234.1235}\)
\(\frac{1235.1236-1}{1235.1236}=1-\frac{1}{1235.1236}\)
DO \(\frac{1}{1234.1235}>\frac{1}{1235.1236}\)=> \(-\frac{1}{1234.1235}< -\frac{1}{1235.1236}\)
=> \(\frac{1234.1235-1}{1234.1235}< \frac{1235.1236-1}{1235.1236}\)