câu hỏi tương tự nhé bạn

bài 3:

ta có:

\(A=\dfrac{a-b}{b^2}\sqrt{\dfrac{a^2b^4}{a^2-2ab+b^2}}\)

\(A=\dfrac{a-b}{b^2}.\dfrac{ab^2}{a-b}=a\)

b/ \(A=\dfrac{\sqrt{3}+\sqrt{11+6\sqrt{2}}-\sqrt{5+2\sqrt{6}}}{\sqrt{2}+\sqrt{6+2\sqrt{5}}-\sqrt{7+2\sqrt{10}}}\)

\(A=\dfrac{\sqrt{3}+\sqrt{\left(3+\sqrt{2}\right)^2}-\sqrt{\left(\sqrt{2}+\sqrt{3}\right)^2}}{\sqrt{2}+\sqrt{\left(\sqrt{5}+1\right)^2}-\sqrt{\left(\sqrt{5}+\sqrt{2}\right)^2}}\)

\(A=\dfrac{3}{1}=3\)