Which of these series is the Maclaurin series for 11−x\frac{1}{1-x}1−x1?
∑n=0∞xn\sum_{n=0}^{\infty} x^n∑n=0∞xn
∑n=0∞(−x)n\sum_{n=0}^{\infty} (-x)^n∑n=0∞(−x)n
∑n=1∞xn\sum_{n=1}^{\infty} x^n∑n=1∞xn
∑n=0∞xnn!\sum_{n=0}^{\infty} \frac{x^n}{n!}∑n=0∞n!xn