What is the 8th term of this sequence?

Find the rate of change. -12/-3=4. 4 is the rate of change. Now that we have -192 as the 4th term, the simple way is to multiply it by 4 four times to get C, -49,152.
The equation for this would be -192(4)^4
You are multiplying by 4 each time.
1) -3 x 4 = -12
2) -12 x 4 = -48
3) -48 x 4 = -192
4) -192 x 4 = -768
5) -768 x 4 = -3072
6) -3072 x 4 = -12288
7) -12288 x 4 = - 49152
8) -12288 x 4 = -196608
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D) -196,608 is your 8th term.
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hope this helps