Answer:
subtract one from the other
Explanation:
You find the difference between points the same way you find any difference: you subtract one from the other.
Points are generally described by an ordered pair. When you subtract one point from the other, you subtract corresponding parts of the ordered pair:
(a, b) - (c, d) = (a-c, b-d)
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Sometimes, when you're interested in finding the difference between points (x, y), you want to do something different with the y-difference than you do with the x-difference.
For example, the slope of a line is calculated as the ratio of the y-difference to the x-difference. The length of a line segment is the root of the sum of the squares of the differences.