Răspuns :
x*e=e*x=x;
x*e=x ==>
xe-x-e+2=x
xe-e=2x-2
e(x-1)=2(x-1)
e=2; (1)
e*x=x ==>
ex-e-x+2=x
ex-e=2x-2
e(x-1)=2(x-1)
e=2; (2)
din (1) si (2) ==> exista e=2 apartine R astfel incat x*2=2*x=x, oricare ar fi x.
Răspuns:x
Explicație pas cu pas:
x*y=xy-x-y+2
x*e=x*e-x-e+2=x
xe-x-x=e-2
xe-2x=e-2
x(e-2)=e-2
x=(e-2)/(e-2)=1
pas2
e*x=ex-e-x+2=x
ex-x-x=e-2
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