Which of the following infinite series are convergent geometric series?
∑n=1∞5⋅(0.9)n−1\sum_{n=1}^{\infty} 5 \cdot (0.9)^{n-1}∑n=1∞5⋅(0.9)n−1
∑n=1∞2⋅(1.1)n−1\sum_{n=1}^{\infty} 2 \cdot (1.1)^{n-1}∑n=1∞2⋅(1.1)n−1
∑n=1∞3⋅(−0.8)n−1\sum_{n=1}^{\infty} 3 \cdot (-0.8)^{n-1}∑n=1∞3⋅(−0.8)n−1
∑n=1∞4⋅(1)n−1\sum_{n=1}^{\infty} 4 \cdot (1)^{n-1}∑n=1∞4⋅(1)n−1