Răspuns:
b) "Demonstrati"???
Explicație pas cu pas:
a) (x+2)(y+2)-2=xy+2x+2y+4-2=xy+2x+2y+2=x*y Adevarat
b)cam neclar
nu stiu dac prin 1/x intelegi 1/x sau x^(-1)
(x+2) (1/x+2)-2=x
(x+2)(1/x+2)=x+2
(x+2)(1/x+2-1)=0
(x+2)(1/x+1)=0
x+2=0...x= -2
1/x+1=0....1/x=-1......x=-1