What is the nnn-th term formula for the geometric sequence 100,−50,25,…100, -50, 25, \dots100,−50,25,…?
an=100⋅(−0.5)n−1a_n = 100 \cdot (-0.5)^{n-1}an=100⋅(−0.5)n−1
an=100⋅(0.5)n−1a_n = 100 \cdot (0.5)^{n-1}an=100⋅(0.5)n−1
an=100⋅(−2)n−1a_n = 100 \cdot (-2)^{n-1}an=100⋅(−2)n−1
an=−50⋅(−0.5)n−1a_n = -50 \cdot (-0.5)^{n-1}an=−50⋅(−0.5)n−1