a) \(\sqrt{8}+\sqrt{15}< \sqrt{9}+\sqrt{16}=3+4=7\)
\(\sqrt{65}-1>\sqrt{64}-1=8-1=7\)
\(\Rightarrow\sqrt{8}+\sqrt{15}< \sqrt{65}-1\)
b) \(\frac{13-2\sqrt{3}}{6}>\frac{13-2\sqrt{4}}{6}=1,5\)
mà 1,52 = 2,25 ; \(\sqrt{2}^2=2\)
\(\Rightarrow1,5>\sqrt{2}\)hay \(\frac{13-2\sqrt{3}}{6}>\sqrt{2}\)