Question

Bài 1 :Rút gọn 

c,(√28 -2√3+√7) x √7 +√84

d,(√6+c,(5) ^ 2 -√125

e, √150  + √1.6 x √ 60 -√6

 

Answer 1

c) \(\left(\sqrt{28}-2\sqrt{3}+\sqrt{7}\right)\cdot\sqrt{7}+\sqrt{84}\)

\(=\left(2\sqrt{7}-2\sqrt{3}+\sqrt{7}\right)\cdot\sqrt{7}+2\sqrt{21}\)

\(=14-2\sqrt{21}+7+2\sqrt{21}\)

\(=21\)

Answer 2

d) \(\left(\sqrt{6}-\sqrt{5}\right)^2-\sqrt{125}\) ??

\(=6+2\sqrt{30}+5-5\sqrt{5}\)

\(=11+2\sqrt{30}-5\sqrt{5}\)

Answer 3

e) \(\sqrt{150}+\sqrt{1,6}\cdot\sqrt{60}-\sqrt{6}\)

\(=5\sqrt{6}+\sqrt{16\cdot6}-\sqrt{6}\)

\(=5\sqrt{6}+4\sqrt{6}-\sqrt{6}\)

\(=8\sqrt{6}\)