Giá trị của B = lim (4 n^ 2 + 3 n + 1)/ ( 3 n − 1 ) ^2 bằng:

ChọnA.

Ta có: \(B = \lim \frac{{4{n^2} + 3n + 1}}{{{{\left( {3n - 1} \right)}^2}}} = \lim \frac{{{n^2}\left( {4 + \frac{3}{n} + \frac{1}{{{n^2}}}} \right)}}{{{n^2}{{\left( {3 - \frac{1}{n}} \right)}^2}}} = \lim \frac{{\left( {4 + \frac{3}{n} + \frac{1}{{{n^2}}}} \right)}}{{{{\left( {3 - \frac{1}{n}} \right)}^2}}} = \frac{{4 + 0 + 0}}{{{{\left( {3 - 0} \right)}^2}}} = \frac{4}{9}\)