Đề sai nha bạn,sửa dấu ":" thanh dấu nhân nha
Có \(\left(\frac{a\sqrt{a}+b\sqrt{b}}{\sqrt{a}+\sqrt{b}}-\sqrt{ab}\right).\left(\frac{\sqrt{a}+\sqrt{b}}{a-b}\right)^2\)
= \(\left(\frac{a\sqrt{a}+b\sqrt{b}-a\sqrt{b}-b\sqrt{a}}{\sqrt{a}+\sqrt{b}}\right).\frac{\left(\sqrt{a}+\sqrt{b}\right)^2}{\left(\sqrt{a}+\sqrt{b}\right)^2.\left(\sqrt{a}-\sqrt{b}\right)^2}\)
=\(\frac{a\left(\sqrt{a}-\sqrt{b}\right)-b\left(\sqrt{a}-\sqrt{b}\right)}{\sqrt{a}+\sqrt{b}}.\frac{1}{\left(\sqrt{a}-\sqrt{b}\right)^2}\)
=\(\frac{\left(\sqrt{a}+\sqrt{b}\right)\left(\sqrt{a}-\sqrt{b}\right)^2}{\sqrt{a}+\sqrt{b}}.\frac{1}{\left(\sqrt{a}-\sqrt{b}\right)^2}\)
=1
Vậy bt k phụ thuộc vào biến
