23. limn→∞(12)n+(13)n+1(12)n+1+(13)n\displaystyle\lim_{n\to\infty}\frac{(\frac12)^n+(\frac13)^{n+1}}{(\frac12)^{n+1}+(\frac13)^n}n→∞lim(21)n+1+(31)n(21)n+(31)n+1의 값은? [2점]