a)
E(x)=[(x²+2)/(x²+4x+4)-x/(x+2)] :[1/(x-2)-3/(x²-4)]=
=[(x²+2)/(x+2)²-x/(x+2)] :[1/(x-2)-3/(x-2)(x+2)]=
=(x²+2-x²-2x)/(x+2)² :(x+2-3)/(x-2)(x+2)=
=(2-2x)/(x+2)² ×(x-2)(x+2)/(x-1)=
=-2(x-1)(x-2)/(x+2)(x-1)=
=-2(x-2)/(x+2)=
=2(2-x)/(x+2)
b) E(x)=x+2
2(2-x)/(x+2) =x+2
4-2x =(x+2)²
4-2x =x²+4x+4
x²+6x=0
x(x+6)=0 x=0
x+6=0 x=-6
