Question

Rút gọn biểu thức: 

a, \(\sqrt{6+4\sqrt{2}}+\sqrt{6-4\sqrt{2}}\)

b, \(\sqrt{\left(1-\sqrt{3}\right)^2}-\sqrt{12+6\sqrt{3}}\)

c, \(4x-\sqrt{x^2-4x+4}\left(vớix\ge2\right)\)

d, \(\frac{x+6\sqrt{x}+9}{x+9}\)\(\left(vớix\ge0,x\ne9\right)\)

e, \(\frac{\sqrt{x^2+4x+4}}{x+2}\)\(\left(vớix\ne-2\right)\)

Answer 1

mk nhầm dấu sửa lại câu c là \(4x-x+2\)=  \(3x+2\)

Answer 2

a,  \(\sqrt{\left(\sqrt{2}\right)^2+2\times2\times\sqrt{2}+2^2}\)+    \(\sqrt{2^2+2\times2\times\sqrt{2}+\left(\sqrt{2}\right)^2}\)

=   \(\sqrt{\left(\sqrt{2}+2\right)^2}\)+    \(\sqrt{\left(2-\sqrt{2}\right)^2}\)

=  \(\sqrt{2}+2+2-\sqrt{2}\)

=  4   

Answer 3

c, \(4x-\sqrt{\left(x-2\right)^2}\)

=  \(4x-x-2\)

=  \(3x-2\)