



 
Francesca, Let's use another number instead of 4. Suppose R = {(a,b): 3 divides ab}. Then (4, 1) is in R because 4 divides 41 = 3. Is (1, 4) in R? For that to be true, 3 would have to divide 14 = (3). It does, since 3x(1) = (3). Therefore (1, 4) is in R to. Good luck,
 


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