Đáp án:
$a)\sqrt{5}+\sqrt{7}>\sqrt{12}\\ b)\sqrt{8}+3<6+\sqrt{2}\\ c)\sqrt{13.15}<14\\ d)\sqrt{27}+\sqrt{6}+1>\sqrt{48}$
Giải thích các bước giải:
$a)(\sqrt{5}+\sqrt{7})^2=12+2\sqrt{35}\\ \sqrt{12}^2=12\\ \Rightarrow \sqrt{5}+\sqrt{7}>\sqrt{12}\\ b)\sqrt{8}+3<\sqrt{9}+3=6<6+\sqrt{2}\\ c)\sqrt{13.15}=\sqrt{(14-1).(14+1)}=\sqrt{14^2-1}<\sqrt{14^2}=14\\ d)\sqrt{27}+\sqrt{6}+1=3\sqrt{3}+\sqrt{6}+1>3\sqrt{3}+\sqrt{3}=4\sqrt{3}=\sqrt{48}$
