When finding the distance between two points, we can use the Distance Formula.
AB=(x2−x1)2+(y2−y1)2
Comparing this to the calculations in the book, we can notice that the square root is missing. The mistake was made in the very first step, which should have looked like the following equation.
AB=(5−1)2+[1−(-3)]2
Now, let's calculate the distance using the corrected starting point.