Question

Rút gọn các biểu thức sau:

\(a,\left(\sqrt{45}+\sqrt{20}-\sqrt{80}\right):\sqrt{5}\)

\(b,\left(\sqrt{5}-\sqrt{3}\right)^2+2\sqrt{15}\)

Answer 1

a.

\(=\left(3\sqrt{5}+2\sqrt{5}-4\sqrt{5}\right):\sqrt{5}\)

\(=\sqrt{5}:\sqrt{5}=1\)

b.

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

Answer 2

a) = \(\left(3\sqrt{5}+2\sqrt{5}-4\sqrt{5}\right):\sqrt{5}\)

= \(\sqrt{5}:\sqrt{5}=1\)

Answer 3

b) = \(\sqrt{5^{2^{ }}}-2.\sqrt{5}.\sqrt{3}+\sqrt{3^2}+2\sqrt{15}\)

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

= 8

Answer 4

toàn bài dễ mak

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