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Answer:
(x, y) ⇒ (x -m, y -n)
Step-by-step explanation:
Reverse the arrow and solve for the x and y on the left:
(x +m, y +n) ⇒ (x, y)
This resolves to two relations:
x + m ⇒ x
x ⇒ x - m . . . . . subtract m
and
y + n ⇒ y
y ⇒ y - n . . . . . . subtract n
Putting these back together, we have ...
(x, y) ⇒ (x -m, y -n) . . . . . maps P'Q' to PQ
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The original translation was right m and up n. The reverse translation is left m and down n. That is what the rule shows.
