Ta có: \(B=\left(3+\frac{a+\sqrt{a}}{\sqrt{a}+1}\right)\left(3-\frac{a-\sqrt{a}}{\sqrt{a}-1}\right)\)
\(=\left(3+\frac{\sqrt{a}\left(\sqrt{a}+1\right)}{\sqrt{a}+1}\right)\left(3-\frac{\sqrt{a}\left(\sqrt{a}-1\right)}{\sqrt{a}-1}\right)\)
\(=\left(3+\sqrt{a}\right)\left(3-\sqrt{a}\right)=9-a\)
Đúng 0
Bình luận (0)
