Answer
23$^{\circ}$49'
Work Step by Step
1. Start from the smallest part, which is the minutes part ('). See whether we need to borrow.
$18' \lt 29'$ Yes, we need to borrow
2. When you borrow, you take one whole degree from 71 degrees, and add 60 minutes to the 18 you already have.
70$^{\circ}$78' - 47$^{\circ}$29' = 23$^{\circ}$49'
