E(n)={(x^2+4x+4)/[x(x+2)]}:(1+ 2/x)=
={[(x+2)^2]/[x(x+2)]}:[(x+2)/x]=
=[(x+2)/x]*[x/(x+2)]=[x(x+2)]/[x(x+2)]=1
E(n)={[(x-2)/x^2 -4)]*[(5x+10)/(x-3)] +1}*[(x-3)/(x+2)]=
={(x-2)/[(x-2)(x+2)] *5[(x+2)/(x-3)] +1}*[(x-3)/(x+2)]=
=[1/(x+2)]*5[(x+2)/(x-3)] +1}*[(x-3)/(x+2)]=
=[5/(x-3) +1]*[(x-3)/(x+2)]=
=[(5+x-3)/(x-3)]*[(x-3)/(x+2)]=
=[(x+2)/(x-3)]*[(x-3)/(x+2)]=
[(x+2)(x-3)]/[(x-3)(x+2)]=1