\(lim\dfrac{\left(n-1\right)^2.\left(7n+2\right)^n}{\left(2n+1\right)^4}\)
\(=lim\dfrac{n^4.\left(\dfrac{1}{n}-\dfrac{1}{n^2}\right).n^n.\left(7+\dfrac{2}{n}\right)^n}{n^4\left(2+\dfrac{1}{n}\right)^4}\)
\(=\dfrac{0}{2}=0\)
mình làm hơi gọn, bạn kh hiểu thì hỏi mình nha