câu 1 : thực hiện phép tính
a) \(\sqrt{50}-\sqrt{54}+\frac{1}{2}\sqrt{72}+\frac{5}{6}\sqrt{216}\)
b) \(\frac{1}{2}\sqrt{48}-\sqrt{32}-\sqrt{75}-\frac{1}{5}\sqrt{50}\)
c)\(\frac{\sqrt{2}-1}{2-\sqrt{2}}\)
d)\(4\sqrt{\frac{3}{2}}-\frac{5}{2}\sqrt{24}+\frac{1}{2}\sqrt{32}\)
e)\(24\sqrt{\frac{2}{3}}+6\sqrt{\frac{3}{2}}-3\sqrt{24}\)
f)\(2\sqrt{12}+3\sqrt{27}-\sqrt{48}\)
g)\(\left(2\sqrt{5}+5\sqrt{2}\right).\sqrt{5}-\sqrt{250}\)
h)\(\frac{3+\sqrt{3}}{3-\sqrt{3}}+\frac{3-\sqrt{3}}{3+\sqrt{3}}\)
k)\(\left(\sqrt{28}-\sqrt{12}+\sqrt{7}\right).\sqrt{7}+2.\sqrt{21}\)
l)\(\frac{2.\sqrt{3}-\sqrt{6}}{\sqrt{8}-2}\)
Ai đó giúp mình với ạ!
a) = \(5\sqrt{2}-3\sqrt{6}+3\sqrt{2}+5\sqrt{6}\)
= \(8\sqrt{2}+2\sqrt{6}\)
b) = \(2\sqrt{3}-4\sqrt{2}-5\sqrt{3}-\sqrt{2}\)
= \(-3\sqrt{3}-5\sqrt{2}\)
c) = \(\frac{\left(\sqrt{2}-1\right)\left(2+\sqrt{2}\right)}{\left(2-\sqrt{2}\right)\left(2+\sqrt{2}\right)}\)
=\(\frac{2\sqrt{2}+2-2-\sqrt{2}}{2^2-\sqrt{2^2}}\)
=\(\frac{\sqrt{2}}{4-2}\) = \(\frac{\sqrt{2}}{2}\)
d) = \(2\sqrt{6}-5\sqrt{6}+2\sqrt{2}\)
=\(-3\sqrt{6}+2\sqrt{2}\)
e) = \(8\sqrt{6}+3\sqrt{6}-6\sqrt{6}=5\sqrt{6}\)
f) = \(4\sqrt{3}+9\sqrt{3}-4\sqrt{3}=9\sqrt{3}\)
g) = \(10+5\sqrt{10}-5\sqrt{10}=10\)
h) = \(\frac{\left(3+\sqrt{3}\right)\left(3+\sqrt{3}\right)}{\left(3-\sqrt{3}\right)\left(3+\sqrt{3}\right)}+\frac{\left(3-\sqrt{3}\right)\left(3-\sqrt{3}\right)}{\left(3+\sqrt{3}\right)\left(3-\sqrt{3}\right)}\)
= \(\frac{9+3\sqrt{3}+3\sqrt{3}+3}{3^2-\sqrt{3^2}}+\frac{9-3\sqrt{3}-3\sqrt{3}+3}{3^2-\sqrt{3^2}}\)
= \(\frac{12+6\sqrt{3}}{9-3}+\frac{12-6\sqrt{3}}{9-3}\)
= \(\frac{12+6\sqrt{3}+12-6\sqrt{3}}{6}\)
= \(\frac{24}{6}=4\)
k) = \(\left(2\sqrt{7}-2\sqrt{3}+\sqrt{7}\right).\sqrt{7}+2\sqrt{21}\)
= \(\left(3\sqrt{7}-2\sqrt{3}\right).\sqrt{7}+2\sqrt{21}\)
= \(21-2\sqrt{21}+2\sqrt{21}=21\)
l) = \(\frac{\left(2\sqrt{3}-\sqrt{6}\right)\left(\sqrt{8}+2\right)}{\left(\sqrt{8}-2\right)\left(\sqrt{8}+2\right)}\)
= \(\frac{4\sqrt{6}+4\sqrt{3}-4\sqrt{3}-2\sqrt{6}}{\sqrt{8^2}-2^2}\)
= \(\frac{2\sqrt{6}}{8-4}=\frac{2\sqrt{6}}{4}=\frac{\sqrt{6}}{2}\)
