Question

rút gọn

a.\(5\sqrt{\dfrac{1}{5}}+\dfrac{1}{2}\sqrt{20}+\sqrt{5}\)

b.\(\sqrt{\dfrac{1}{2}}+\sqrt{4,5}+\sqrt{12,5}\)

c.\(\sqrt{20}-\sqrt{45}+3\sqrt{18}+\sqrt{72}\)

d.\(0,1.\sqrt{200}+2.\sqrt{0,08}+0,4.\sqrt{50}\)

Answer 1

a, \(5\sqrt{\dfrac{1}{5}}+\dfrac{1}{2}\sqrt{20}+\sqrt{5}\)

\(=\sqrt{5}+\dfrac{1}{2}.2\sqrt{5}+\sqrt{5}\)

\(=3\sqrt{5}\)

b, \(\sqrt{\dfrac{1}{2}}+\sqrt{4,5}+\sqrt{12,5}\)

\(=\sqrt{0,5}+3\sqrt{0,5}+5\sqrt{0,5}=9\sqrt{0,5}\)

c, \(\sqrt{20}-\sqrt{45}+3\sqrt{18}+\sqrt{72}\)

\(=2\sqrt{5}-3\sqrt{5}+3\sqrt{18}+2\sqrt{18}\)

\(=-\sqrt{5}+5\sqrt{18}\)

d, \(0,1.\sqrt{200}+2\sqrt{0,08}+0,4\sqrt{50}\)

\(=\sqrt{0,01.200}+0,2.\sqrt{2}+0,4.5\sqrt{2}\)

\(=\sqrt{2}+0,2\sqrt{2}+2\sqrt{2}=3,2\sqrt{2}\)

Chúc bạn học tốt!!!