Bill has been saving $7 each week. today he spent $77of the savings, and now he has $42 left. for how many weeks has he been saving

17. Bill has been saving for 17 weeks. $77 was from 11 weeks (7×11=77), and $42 is from 6 weeks (7×6=42). $77+$42=$119, 119÷7=17

aloha~! my name is zalgo and i am here to you out on this amazing day. to answer your question, yes, nonzero numbers can have a greatest common factor and that would be 1. still don't get it? let me considering every number is divisible by 1 and hence every number has 1 as a factor of theirs. so, if 2 nonzero numbers didn't share any gcf (greatest common factor), they would still have a factor in common and that would be 1.

i hope that this ! : p

"stay and stay proud! " - zalgo

(by the way, do you mind marking me as brainliest? i'd greatly appreciate it! mahalo! x3)