John works part time for a moving company. one day he had to move 34 boxes from a truck. after moving some boxes, he took a lunch break and told his boss he had only 15 boxes left to move. which equation would we use to solve how many boxes be moved before his break
A. 15-x=34
B. 34+x=15
C. 34-x=15
D. 15+34=x