Answer:
|2-(-7)| = 9
Explanation:
The quantity inside the absolute value operator is 9 only in the second given possible answer. Think: from -7 you must travel 7 units to the right to reach the origin. Then, from the origin you must travel another 2 units to the right. Thus, the distance traveled is 7+2 = 9, which is equivalent to |2-(-7)|.