\(\frac{1}{7}\sqrt{51}< \frac{1}{7}\sqrt{64}=\frac{1}{7}.8=\frac{8}{7}\)
\(\frac{1}{9}\sqrt{150}>\frac{1}{9}\sqrt{144}=\frac{1}{9}.12=\frac{4}{3}\)
\(1+\frac{1}{3}>1+\frac{1}{7}\Rightarrow\frac{4}{3}>\frac{8}{7}\)
Do đó: \(\frac{1}{7}\sqrt{51}< \frac{1}{9}\sqrt{150}\)