12. -5, -20, -80,underline ( ),underline ( ),underline ( )

This question is a sequence problem. The given sequence is -5, -20, -80. We can see that each term is 4 times the previous term. So, the next term would be -80 * 4 = -320, then -320 * 4 = -1280, and finally -1280 * 4 = -5120. Therefore, the missing terms in the sequence are -320, -1280, and -5120.