Question

Se considera multimea A={-1;2} si B={a;b}. Daca AxB=BxA , atunci a+b = ....

Answer 1

[tex]A \times B = B \times A \Leftrightarrow A=B\\ \lbrace -1;2\rbrace = \lbrace a;b \rbrace \Rightarrow a=-1, \; b=2 \Rightarrow a+b=2-1=1[/tex]