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a: \(=3\sqrt{5}+2\sqrt{5}-2\sqrt{5}=3\sqrt{5}\)
b: \(=2\sqrt{2}+2\sqrt{2}+5\sqrt{2}=9\sqrt{2}\)
c: \(=4\sqrt{3}+3\sqrt{3}-3\sqrt{5}+2\sqrt{5}=7\sqrt{3}-\sqrt{5}\)
d: \(=5\sqrt{3}+4\sqrt{3}-10\sqrt{3}=-\sqrt{3}\)
e: \(=\left(\sqrt{7}-2\sqrt{3}\right)\cdot\sqrt{7}+2\sqrt{21}\)
=7-2*căn 21+2*căn 21
=7
f: \(=\left(2\sqrt{11}-3\sqrt{2}\right)\cdot\sqrt{11}+3\sqrt{22}\)
=22-3*căn 22+3*căn 22
=22
a) \(3\sqrt{5}+\sqrt{20}-2\sqrt{5}\)
\(=3\sqrt{5}+2\sqrt{5}-2\sqrt{5}\)
\(=3\sqrt{5}\)
b) \(2\sqrt{2}+\sqrt{8}+\sqrt{50}\)
\(=2\sqrt{2}+2\sqrt{2}+5\sqrt{2}\)
\(=9\sqrt{5}\)
c) \(4\sqrt{3}+\sqrt{27}-\sqrt{45}+2\sqrt{5}\)
\(=4\sqrt{3}+3\sqrt{3}-3\sqrt{5}+2\sqrt{5}\)
\(=7\sqrt{3}-\sqrt{5}\)
d) \(\sqrt{75}+\sqrt{48}-\sqrt{300}\)
\(=5\sqrt{3}+4\sqrt{3}-10\sqrt{3}\)
\(=-\sqrt{3}\)
e) \(\left(\sqrt{28}-\sqrt{12}-\sqrt{7}\right)\sqrt{7}+2\sqrt{21}\)
\(=\left(2\sqrt{7}-2\sqrt{3}-\sqrt{7}\right)\sqrt{7}+2\sqrt{21}\)
\(=\left(\sqrt{7}-2\sqrt{3}\right)\sqrt{7}+2\sqrt{21}\)
\(=7-2\sqrt{21}+2\sqrt{21}\)
\(=7\)
f) \(\left(\sqrt{99}-\sqrt{18}-\sqrt{11}\right)\sqrt{11}+3\sqrt{22}\)
\(=\left(3\sqrt{11}-3\sqrt{2}-\sqrt{11}\right)\sqrt{11}+3\sqrt{22}\)
\(=\left(2\sqrt{11}-3\sqrt{2}\right)\sqrt{11}+3\sqrt{22}\)
\(=22-3\sqrt{22}+3\sqrt{22}\)
\(=22\)
g) \(3\sqrt{45}-5\sqrt{125x}+7\sqrt{20x}+28\)
\(=9\sqrt{5}-25\sqrt{5x}+14\sqrt{5x}+28\)
\(=9\sqrt{5}-11\sqrt{5x}+28\)
6: \(=3\cdot2\sqrt{3}-4\cdot3\sqrt{3}+5\cdot4\sqrt{3}=14\sqrt{3}\)
7: \(=2\sqrt{3}+5\sqrt{3}-4\sqrt{3}=3\sqrt{3}\)
8: \(=2\cdot4\sqrt{2}+4\cdot2\sqrt{2}-5\cdot3\sqrt{2}=\sqrt{2}\)
9: \(=3\cdot2\sqrt{5}-2\cdot3\sqrt{5}+4\sqrt{5}=4\sqrt{5}\)
10: \(=2\cdot2\sqrt{6}-2\cdot3\sqrt{6}+3\sqrt{6}-5\sqrt{6}=-4\sqrt{6}\)
a) \(\sqrt{12}+5\sqrt{3}-\sqrt{48}=\sqrt{2^2\cdot3}+5\sqrt{3}-\sqrt{4^2\cdot3}\)
\(=2\sqrt{3}+5\sqrt{3}-4\sqrt{3}=\left(2+5-4\right)\sqrt{3}=3\sqrt{3}\)
b) \(5\sqrt{5}+\sqrt{20}-3\sqrt{45}=5\sqrt{5}+\sqrt{2^2\cdot5}-3\sqrt{3^2\cdot5}\) \(=5\sqrt{5}+2\sqrt{5}-9\sqrt{5}=-2\sqrt{5}\)
c)
\(2\sqrt{32}+4\sqrt{8}-5\sqrt{18}=2\sqrt{4^2\cdot2}+4\sqrt{2^2\cdot2}-5\sqrt{3^2\cdot2}\) \(=8\sqrt{2}+8\sqrt{2}-15\sqrt{2}=\sqrt{2}\)
d)\(\sqrt{2^2\cdot3}+\sqrt{5^2\cdot3}-\sqrt{3^2\cdot3}=2\sqrt{3}+5\sqrt{3}-3\sqrt{3}=4\sqrt{3}\)
a: \(=3\sqrt{3}-2\sqrt{3}+4\sqrt{3}-5\sqrt{3}=2\sqrt{3}\)
\(\left(\sqrt{12}+\sqrt{27}-\sqrt{18}\right)\cdot3\\ =(\sqrt{4\cdot3}+\sqrt{9\cdot3}-\sqrt{6}\cdot\sqrt{3})\cdot\sqrt{3}\\ =\left(2\sqrt{3}+3\sqrt{3}-\sqrt{6}\cdot\sqrt{3}\right)\cdot\sqrt{3}\\ =2\cdot3+3\cdot3-\sqrt{6}\cdot3\\ =6+9-3\sqrt{6}\\ =15-3\sqrt{6}\)
\(\left(15\sqrt{20}-3\sqrt{45}+2\sqrt{5}\right):\sqrt{5}\\ =\left(15\sqrt{4\cdot5}-3\sqrt{9\cdot5}+2\sqrt{5}\right):\sqrt{5}\\ =\left(30\sqrt{5}-9\sqrt{5}+2\sqrt{5}\right):\sqrt{5}\\ =30-9+2\\ =23\)