60 000 đồng

\(\left(1+\dfrac{a+\sqrt{a}}{\sqrt{a}+1}\right)\left(1-\dfrac{a-\sqrt{a}}{1-\sqrt{a}}\right)\) với \(a\ge0;a\ne1\)

\(=\left[1+\dfrac{\sqrt{a}\left(\sqrt{a}+1\right)}{\sqrt{a}+1}\right]\left[1+\dfrac{\sqrt{a}\left(\sqrt{a}-1\right)}{\sqrt{a}-1}\right]\)

\(=\left(1+\sqrt{a}\right)\left(1+\sqrt{a}\right)\)

\(=\left(1+\sqrt{a}\right)^2\)