Nina had 17 marbles in a bag. Her mother put a handful of marbles in the bag. When Nina counts her marbles, she discovers she now has 34 of them. Which of the following equations will help Nina solve for the number of marbles, m, that her mom put in the bag?
17 + 34 = m
17 + m = 34
17m = 34
m − 17 = 34