a. Ta có: \(VT=\left(\dfrac{a\sqrt{a}-b\sqrt{b}}{\sqrt{a}-\sqrt{b}}+\sqrt{ab}\right)\left(\dfrac{\sqrt{a}-\sqrt{b}}{a-b}\right)^2=\left[\dfrac{\left(\sqrt{a}-\sqrt{b}\right)\left(a+\sqrt{ab}+b\right)}{\sqrt{a}-\sqrt{b}}+\sqrt{ab}\right]\left[\dfrac{\sqrt{a}-\sqrt{b}}{\left(\sqrt{a}-\sqrt{b}\right)\left(\sqrt{a}+\sqrt{b}\right)}\right]^2=\left(a+2\sqrt{ab}+b\right).\left(\dfrac{1}{\sqrt{a}+\sqrt{b}}\right)^2=\)
\(\left(\sqrt{a}+\sqrt{b}\right)^2.\dfrac{1}{\left(\sqrt{a}+\sqrt{b}\right)^2}=1=VP\)
=> đpcm.
Đúng 0
Bình luận (0)
