a = -8; r = -4
A) -8, 32, -128, 512, -2048
B) -8, -32, -128, 512, -2048
C) -4, 32, -128, 512, -2048
D) -8, -12, -16, -20, -24

Question

Quizplus · Accepted Answer

The formula for the n-th term of a geometric sequence is given by an = a*r^(n-1). Substituting a=-8 and r=-4, we get the sequence as -8, 32, -128, 512, -2048, which matches Option A. Option B is incorrect because it has the wrong signs for the terms after the first one. Option C has the wrong initial term of -4 instead of -8. Option D is also incorrect because it has a linear sequence with a common difference of -4, whereas we have a geometric sequence with a common ratio of -4.

A = -8; R = -4