Question

E(x)=$( \frac{x+3}{ x^{2} +6x+9} - \frac{x}{x+3} ) * \frac{x+3}{-3x-3x+6}$

Answer 1

E(x)=[(x+3)/(x²+6x+9)-x/(x+3)] × (x+3)/(-3x²-3x+6)=
=[(x+3)/(x+3)²-x/(x+3)] × (x+3)/(-3)(x²+x-2)=
=[1/(x+3)-x/(x+3)] × (x+3)/(-3)(x-1)(x+2)=
=(1-x)/(x+3)] × (x+3)/3(1-x)(x+2)=
=1/3(x+2)