Răspuns :
rezulta E(x)=x/3+[2(x+3)/3x]:(x+3)/x²
E(x)=x/3+[2(x+3)/3x]·[x²/(x+3) simplificam
E(x)=x/3+2x/3
E(x)=3x/3=x
E(x)=x/3+[2(x+3)/3x]·[x²/(x+3) simplificam
E(x)=x/3+2x/3
E(x)=3x/3=x
x 2x+6 1 3
E(x)= ----- + ----------- : ( ------ + ------ )
3 3x x x²
x 2(x+3) x²
E(x)= ------ + ------------- · --------
3 3x x+3
x 2x 3x
E(x)= ------ + ------- = ------
3 3 3
E(x)=x
E(x)= ----- + ----------- : ( ------ + ------ )
3 3x x x²
x 2(x+3) x²
E(x)= ------ + ------------- · --------
3 3x x+3
x 2x 3x
E(x)= ------ + ------- = ------
3 3 3
E(x)=x