Respuesta :

factoring we get 

(x + 2)(x + 1) / (x + 1)(x + 1)

The excluded value is x = -1

Answer:  The required value of x is [tex]x=-1.[/tex]

Step-by-step explanation:  We are given to find the excluded value for the following rational expression:

[tex]E=\dfrac{x^2+3x+2}{x^2+2x+1}.[/tex]

First, we need to factorize both numerator and denominator and then we should check the values of x for which the expression becomes undefined.

We have

[tex]E\\\\=\dfrac{x^2+3x+2}{x^2+2x+1}\\\\\\=\dfrac{x^2+2x+x+2}{x^2+x+x+1}\\\\\\=\dfrac{x(x+2)+1(x+2)}{x(x+1)+1(x+1)}\\\\\\=\dfrac{(x+2)(x+1)}{(x+1)(x+1)}.[/tex]

Now, we can cancel [tex](x+1)[/tex] by [tex](x+1)[/tex], only if [tex]x\neq 1,[/tex] because

if [tex]x=-1,[/tex] then  [tex]x+1=0[/tex] and we cannot divide 0 by 0.

Therefore, if [tex]x\neq 1,[/tex] then

[tex]E=\dfrac{(x+2)(x+1)}{(x+1)(x+1)}=\dfrac{x+2}{x+1},[/tex]

which is again well-defined because [tex]x\neq -1[/tex] and so the denominator never become zero.

Thus, the excluded value of x is  [tex]x=-1.[/tex]