22) \(\left(\sqrt[]{5}-\sqrt[]{2}\right)\left(\sqrt[]{2}+\sqrt[]{5}\right)+\sqrt[]{5}.\sqrt[]{10}.\sqrt[]{8}\)
\(=\left(5-2\right).\sqrt[]{5.10.8}\)
\(=3.\sqrt[]{400}=3.\sqrt[]{20^2}=3.20=60\)
18) \(\left(\sqrt[]{99}-\sqrt[]{18}-\sqrt[]{11}\right)\sqrt[]{11}+3\sqrt[]{22}\)
\(=\sqrt[]{99}.\sqrt[]{11}-\sqrt[]{18}.\sqrt[]{11}-\sqrt[]{11}.\sqrt[]{11}+3\sqrt[]{2.11}\)
\(=\sqrt[]{9.11}.\sqrt[]{11}-\sqrt[]{2.9}.\sqrt[]{11}-\sqrt[]{11}.\sqrt[]{11}+3\sqrt[]{2}.\sqrt[]{11}\)
\(=3.11-3\sqrt[]{2}.\sqrt[]{11}-11+3\sqrt[]{2}.\sqrt[]{11}\)
\(=33-11=22\)
17: \(\left(\sqrt{12}-2\sqrt{18}+5\sqrt{3}\right)\cdot\sqrt{3}+5\sqrt{6}\)
\(=\left(2\sqrt{3}-6\sqrt{2}+5\sqrt{3}\right)\cdot\sqrt{3}+5\sqrt{6}\)
\(=\left(7\sqrt{3}-6\sqrt{2}\right)\cdot\sqrt{3}+5\sqrt{6}\)
\(=21-6\sqrt{6}+5\sqrt{6}=21-\sqrt{6}\)
19: \(\left(\sqrt{8}-3\sqrt{2}+\sqrt{10}\right)\cdot\sqrt{2}-\sqrt{5}\)
\(=\left(2\sqrt{2}-3\sqrt{2}+\sqrt{10}\right)\cdot\sqrt{2}-\sqrt{5}\)
\(=-2+\sqrt{20}-\sqrt{5}=-2+2\sqrt{5}-\sqrt{5}=-2+\sqrt{5}\)
20: \(\left(\sqrt{24}-\sqrt{48}-\sqrt{6}\right)\cdot\sqrt{6}+12\sqrt{2}\)
\(=\left(2\sqrt{6}-\sqrt{6}-4\sqrt{3}\right)\cdot\sqrt{6}+12\sqrt{2}\)
\(=6-4\sqrt{18}+12\sqrt{2}=6\)
21: \(\left(2\sqrt{112}-5\sqrt{7}+2\sqrt{63}-2\sqrt{28}\right)\cdot\sqrt{7}\)
\(=\left(2\cdot4\sqrt[]{7}-5\sqrt{7}+2\cdot3\sqrt{7}-2\cdot2\sqrt{7}\right)\cdot\sqrt{7}\)
\(=5\sqrt{7}\cdot\sqrt{7}=35\)
rút gọn giúp mình vs ạ 
Rút gọn giúp mình với ạ
rút gọn biểu thức, giúp e với ạ :<
