xueyezhanshi
幼苗
共回答了17个问题采纳率:94.1% 举报
A={(1,2),(1,4),(1,6),(2,1),(2,3),(2,5),(3,2),(3,5),(4,1),(4,3),(4,5),(5,2),(5,4),(5,6)}
B={(1,1),(2,2),(3,3),(4,4),(5,5),(6,6)}
C={(1,1),(1,2),(1,3),(1,4),(1,5),(1,6),(2,1),(2,2),(2,3),(2,4),(2,5),(2,6),(3,1),(3,2),(3,3),(3,4),(3,5),(3,6),(4,1),(4,2),(4,3),(4,4),(4,5),(5,1),(5,2),(5,3),(5,4),(6,1),(6,2),(6,3)}
B-A=B
B+C=BU{(5,5),(6,6)}
1年前
追问
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