Define set from given function and a subset. Abstract math

beatka6
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Homework Statement


Let f: Z to ZxZ be the function defined f(t)=(3t, 3t+1) . Let B denote the subset of ZxZ defined by B={ (5m, 5m+1) : m is an element of Z}. Determine f^-1(B). This means that you should define set S with a property of S=f^-1(B). In addition, your definition of S should make no mention of the function f.


Homework Equations





The Attempt at a Solution


From what I understand first we have to find f(B), but B is a subset of ZxZ not Z therefore I don't know what to do with this. Please help.
 
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f^{-1}(B) is defined as {t\inZ | f(t)\inB}, i.e., the collection of t's such that f(t) is in B.
 
It says that it should have no mention of f in the defined set.
 
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