Question

Pe R se considera legea de compozitie XoY=(X-2)(Y+2)+2. Sa se demonstreze ca Xo2=2 oricare ar fi x numar real

Answer 1

[tex]xoy=(x-2)(y+2)+2=xy+2x-2y-4+2=xy+2x-2y-2 xo2=2 2x+2x-4-2-2=0 4x-8=0 4x=8 x=8/4 x=2[/tex]