lim \frac{2n-3^{n}}{n-2^{n}}=lim \frac{2-3\times \frac{1^{n}}{n}}{1-2\times \frac{1^{n}}{n}}=\frac{2-3\times 0}{1-2\times 0}=\frac{a}{b}2 1
lim \frac{2n-3^{n}}{n-2^{n}}=lim \frac{2-3\times \frac{1^{n}}{n}}{1-2\times \frac{1^{n}}{n}}=\frac{2-3\times 0}{1-2\times 0}=2