\(H=\frac{\sqrt{2+\sqrt{3}}-\sqrt{2-\sqrt{3}}}{\sqrt{2+\sqrt{3}}+\sqrt{2-\sqrt{3}}}-\frac{\sqrt{2+\sqrt{3}}+\sqrt{2-\sqrt{3}}}{\sqrt{2+\sqrt{3}}-\sqrt{2-\sqrt{3}}}\)

\(H=\frac{\left(\sqrt{2+\sqrt{3}}-\sqrt{2-\sqrt{3}}\right)^2}{\left(\sqrt{2+\sqrt{3}}+\sqrt{2-\sqrt{3}}\right)\left(\sqrt{2+\sqrt{3}}-\sqrt{2-\sqrt{3}}\right)}\)\(-\frac{\left(\sqrt{2+\sqrt{3}}+\sqrt{2-\sqrt{3}}\right)^2}{\left(\sqrt{2+\sqrt{3}}+\sqrt{2-\sqrt{3}}\right)\left(\sqrt{2+\sqrt{3}}-\sqrt{2-\sqrt{3}}\right)}\)(cái này cùng dòng với cái phía trên)

\(H=\frac{\left(\sqrt{2+\sqrt{3}}-\sqrt{2-\sqrt{3}}\right)^2-\left(\sqrt{2+\sqrt{3}}+\sqrt{2-\sqrt{3}}\right)^2}{\left(\sqrt{2+\sqrt{3}}+\sqrt{2-\sqrt{3}}\right)\left(\sqrt{2+\sqrt{3}}-\sqrt{2-\sqrt{3}}\right)}\)

\(H=\frac{\left(\sqrt{2+\sqrt{3}}-\sqrt{2-\sqrt{3}}\right)^2-\left(\sqrt{2+\sqrt{3}}+\sqrt{2-\sqrt{3}}\right)^2}{2\sqrt{3}}\)

\(H=\frac{-4}{2\sqrt{3}}\)

\(H=\frac{-2}{\sqrt{3}}\)

\(H=-\frac{2\sqrt{3}}{3}\)

Đặt \(A=\sqrt{2+\sqrt{3}}+\sqrt{2-\sqrt{3}}\)

\(A^2=2+\sqrt{3}+2\sqrt{\left(2+\sqrt{3}\right)\left(2-\sqrt{3}\right)}+2-\sqrt{3}\)

\(A^2=4+2\sqrt{4+2\sqrt{3}-2\sqrt{3}-3}\)

\(A^2=4+2=6\)

\(A=\sqrt{6}\)

Đặt \(B=\sqrt{2+\sqrt{3}}-\sqrt{2-\sqrt{3}}\)

\(B^2=2+\sqrt{3}-2\sqrt{\left(2+\sqrt{3}\right)\left(2-\sqrt{3}\right)}+2-\sqrt{3}\)

\(B^2=4-2\sqrt{4+2\sqrt{3}-2\sqrt{3}-3}\)

\(B^2=4-2\sqrt{1}=4-2=2\)

\(B=\sqrt{2}\)

Thay vào H 

\(\Rightarrow H=\frac{\sqrt{2}}{\sqrt{6}}-\frac{\sqrt{6}}{\sqrt{2}}=\frac{1}{\sqrt{3}}-\sqrt{3}=\frac{1-3}{\sqrt{3}}=\frac{-2}{\sqrt{3}}\)

\(\frac{A}{\sqrt{2}}=\frac{2+\sqrt{3}}{2+\sqrt{4+2\sqrt{3}}}+\frac{2-\sqrt{3}}{2-\sqrt{4-2\sqrt{3}}}\)

 =\(\frac{2+\sqrt{3}}{3+\sqrt{3}}+\frac{2-\sqrt{3}}{3-\sqrt{3}}\) =\(\frac{\left(2+\sqrt{3}\right)\left(3-\sqrt{3}\right)+\left(2-\sqrt{3}\right)\left(3+\sqrt{3}\right)}{\left(3+\sqrt{3}\right)\left(3-\sqrt{3}\right)}\) =\(\frac{6}{6}=1\)

\(\Rightarrow A=\sqrt{2}\)

a,

\(\frac{\sqrt{6}\left(\sqrt{3}-1\right)}{\sqrt{3}\left(\sqrt{3}-1\right)}+\sqrt{\frac{\left(2-\sqrt{2}\right)^2}{\left(2+\sqrt{2}\right).\left(2-\sqrt{2}\right)}}\)

=\(\sqrt{2}+\frac{2-\sqrt{2}}{\sqrt{2}}\)

=\(\sqrt{2}+\frac{\sqrt{2}\left(\sqrt{2}-1\right)}{\sqrt{2}}\)

=\(\sqrt{2}+\sqrt{2}-1\)

=\(2\sqrt{2}-1\)

còn tiếp

b=,\(\frac{6\sqrt{3}}{3}-\frac{\sqrt{3}\left(1-\sqrt{3}\right)}{\sqrt{3}}-\frac{\sqrt{6}\left(\sqrt{2}-\sqrt{3}\right)}{\sqrt{2}-\sqrt{3}}\)

=\(6-1+\sqrt{3}-\sqrt{6}\)

=\(5+\sqrt{3}+\sqrt{6}\)

b/ \(\frac{1}{\sqrt{1}+\sqrt{2}}+\frac{1}{\sqrt{2}+\sqrt{3}}+...+\frac{1}{\sqrt{n}+\sqrt{n+1}}\)

\(=\sqrt{2}-\sqrt{1}+\sqrt{3}-\sqrt{2}+...+\sqrt{n+1}-\sqrt{n}\)

\(=\sqrt{n+1}-1\)

Câu a quy đồng từ từ từ phải qua trái là ra

Dễ thấy x có tử = 2; mẫu = 1. Vậy x = 2.

\(A=\left(2^{500}+2^{500}\right)^{2000}=2^{501.2000}\)

eo ơi Mr Lazy nhìn sao ra tớ nhìn ko hỉu nỗi

a)

\(\frac{\sqrt{4-2\sqrt{3}}}{\sqrt{6}-\sqrt{2}}=\frac{\sqrt{3+1-2\sqrt{3.1}}}{\sqrt{2}(\sqrt{3}-1)}=\frac{\sqrt{(\sqrt{3}-1)^2}}{\sqrt{2}(\sqrt{3}-1)}=\frac{\sqrt{3}-1}{\sqrt{2}(\sqrt{3}-1)}=\frac{1}{\sqrt{2}}=\frac{\sqrt{2}}{2}\)

\(\sqrt{6+2\sqrt{5}-\sqrt{29-12\sqrt{5}}}=\sqrt{6+2\sqrt{5}-\sqrt{20+9-2\sqrt{20.9}}}\)

\(=\sqrt{6+2\sqrt{5}-\sqrt{(\sqrt{20}-3)^2}}=\sqrt{6+2\sqrt{5}-(\sqrt{20}-3)}\)

\(=\sqrt{9}=3\)

\(\Rightarrow P=\frac{\sqrt{2}}{2}+3\)

b)

\(\frac{2}{\sqrt{3}-1}-\frac{52}{3\sqrt{3}-1}+\frac{12}{3-\sqrt{3}}=\frac{2(\sqrt{3}+1)}{(\sqrt{3}-1)(\sqrt{3}+1)}-\frac{52(3\sqrt{3}+1)}{(3\sqrt{3}-1)(3\sqrt{3}+1)}+\frac{12(3+\sqrt{3})}{(3-\sqrt{3})(3+\sqrt{3})}\)

\(=\frac{2(\sqrt{3}+1)}{2}-\frac{52(3\sqrt{3}+1)}{26}+\frac{12(3+\sqrt{3})}{6}\)

\(=\sqrt{3}+1-2(3\sqrt{3}+1)+2(3+\sqrt{3})=9\sqrt{3}+9=5-3\sqrt{3}\)

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

c)

\(P=\left[\frac{\sqrt{2}(\sqrt{2}+1)}{\sqrt{2}+1}+1\right]\left[\frac{\sqrt{2}(\sqrt{2}-1)}{\sqrt{2}-1}-1\right]\)

\(=(\sqrt{2}+1)(\sqrt{2}-1)=2-1=1\)

d)

\(P\sqrt{2}=\sqrt{18+2\sqrt{17}}-\sqrt{18-2\sqrt{17}}-2=\sqrt{17+1+2\sqrt{17.1}}-\sqrt{17+1-2\sqrt{17.1}}-2\)

\(=\sqrt{(\sqrt{17}+1)^2}-\sqrt{(\sqrt{17}-1)^2}-2=(\sqrt{17}+1)-(\sqrt{17}-1)-2=0\)

\(\Rightarrow P=0\)

đ)

\(2+\sqrt{4+\sqrt{6+2\sqrt{5}}}=2+\sqrt{4+\sqrt{5+1+2\sqrt{5.1}}}=2+\sqrt{4+\sqrt{(\sqrt{5}+1)^2}}\)

\(=2+\sqrt{4+\sqrt{5}+1}=2+\sqrt{5+\sqrt{5}}\)

\(\Rightarrow P=(2+\sqrt{5+\sqrt{5}})(\sqrt{10}-\sqrt{2})\), cái số này rút gọn không có ý nghĩa, sẽ ra số rất xấu, bạn xem lại đề.

e)

\(P=\frac{\sqrt{2}+\sqrt{3}+2+2+\sqrt{6}+\sqrt{8}}{\sqrt{2}+\sqrt{3}+\sqrt{4}}=\frac{(\sqrt{2}+\sqrt{3}+\sqrt{4})+(\sqrt{4}+\sqrt{6}+\sqrt{8})}{\sqrt{2}+\sqrt{3}+\sqrt{4}}\)

\(\frac{(\sqrt{2}+\sqrt{3}+\sqrt{4})+\sqrt{2}(\sqrt{2}+\sqrt{3}+\sqrt{4})}{\sqrt{2}+\sqrt{3}+\sqrt{4}}=\frac{(\sqrt{2}+\sqrt{3}+\sqrt{4})(1+\sqrt{2})}{\sqrt{2}+\sqrt{3}+\sqrt{4}}=1+\sqrt{2}\)