If a geometric sequence has a1=−2a_1 = -2a1=−2 and r=−2r = -2r=−2, what are the first three terms?
2,−4,82, -4, 82,−4,8
−2,−4,−8-2, -4, -8−2,−4,−8
−2,4,−8-2, 4, -8−2,4,−8
−2,4,8-2, 4, 8−2,4,8