Cho biết ​\(\begin{array}{l} B = \frac{{{n^2} + 7n + 6}}{{{n^3} + 6{n^2} - n - 6}} \end{array}\). Tính B khi n=1000001

* Hướng dẫn giải

 \(\begin{array}{l} B = \frac{{{n^2} + 7n + 6}}{{{n^3} + 6{n^2} - n - 6}} = \frac{{(n + 1)(n + 6)}}{{(n + 6)\left( {{n^2} - 1} \right)}} = \frac{1}{{n - 1}}\\ n = 1000001 \Rightarrow B = \frac{1}{{1000001 - 1}} = \frac{1}{{1000000}} \end{array}\)