a) \(\frac{33}{131}>\frac{33}{132}=\frac{1}{4}\); \(\frac{53}{217}< \frac{53}{212}=\frac{1}{4}\)
Từ đó suy ra \(\frac{33}{131}>\frac{53}{217}\)
b) \(B< \frac{15}{17}+\frac{10}{17}+\frac{8}{17}=\frac{15+10+8}{17}=\frac{33}{17}< \frac{34}{17}=2^{\left(đpcm\right)}\)