Question

[dương vũ]

 Rút gọn các biểu thức sau :

1 )  \(\sqrt{80}\)+\(\sqrt{20}\)-\(\sqrt{5}\)-5\(\sqrt{45}\)

2 ) 4\(\sqrt{20}\)-3\(\sqrt{125}\)+5\(\sqrt{45}\)-15\(\sqrt{\frac{1}{5}}\)

3 ) (7\(\sqrt{48}\)+3\(\sqrt{27}\)-2\(\sqrt{12}\)) :\(\sqrt{3}\)

4 ) \(\sqrt{343a}\)+\(\sqrt{63a}\)-\(\sqrt{28a}\)\(\left(a\ge0\right)\)

5 ) -\(\sqrt{36a}\)-\(\frac{1}{3}\).\(\sqrt{54a}\)+\(\frac{1}{5}\).\(\sqrt{150a}\)\(\left(a\ge0\right)\)

6 ) \(2\)\(\sqrt{48}\) -\(4\)\(\sqrt{27}\)+\(\sqrt{75}\)+\(\sqrt{12}\)

Answer 1

[Tuyển Trần Thị]

1,\(4\sqrt{5}+2\sqrt{5}-\sqrt{5}-15\sqrt{5}=-10\sqrt{5}\)

2,\(8\sqrt{5}-15\sqrt{5}+15\sqrt{5}-3\sqrt{5}=5\sqrt{5}\)

3,\(\left(28\sqrt{3}+9\sqrt{3}-4\sqrt{3}\right):\sqrt{3}=33\) 

4,\(7\sqrt{7a}+3\sqrt{7a}-2\sqrt{7a}=8\sqrt{7a}\)

5,\(-6\sqrt{a}-\sqrt{6a}+\sqrt{6a}=-6\sqrt{a}\)

6,\(8\sqrt{3}-12\sqrt{3}+5\sqrt{3}+2\sqrt{3}=3\sqrt{3}\)