Respuesta :

Part a)

Explain the error in this simplification.

Given the simplified expression

[tex]1-\frac{2}{x-2}=\frac{x+1}{x+2}[/tex]

[tex]1-2\left(x+2\right)=\left(x+1\right)\left(x-2\right)[/tex]

[tex]\:1-2x-4=x^2-x-2[/tex]

[tex]-2x-3=x^2-x-2\:\:[/tex]

[tex]0=x^2-2x-2\:\:[/tex]

[tex]0=\left(x-1\right)\left(x-1\right)[/tex]

[tex]x=1[/tex]

Identifying the Main Error

[tex]1-\frac{2}{x-2}=\frac{x+1}{x+2}[/tex]

[tex]1-2\left(x+2\right)=\left(x+1\right)\left(x-2\right)[/tex]   ← ERROR Starts here

Here is the Explanation of the Error

[tex]\mathrm{The\:equation\:should\:have\:been\:Multiplied\:by\:LCM=}\left(x-2\right)\left(x+2\right)[/tex]. In your case you wrongly multiply the equation.

CORRECTION

HERE IS HOW YOU SHOULD HAVE MULTIPLIED BY LCM = (x-2)(x+2):

[tex]1-\frac{2}{x-2}=\frac{x+1}{x+2}[/tex]

[tex]1\cdot \left(x-2\right)\left(x+2\right)-\frac{2}{x-2}\left(x-2\right)\left(x+2\right)=\frac{x+1}{x+2}\left(x-2\right)\left(x+2\right)[/tex]

[tex]\left(x-2\right)\left(x+2\right)-2\left(x+2\right)=\left(x+1\right)\left(x-2\right)[/tex]

Part b)

Show your work as you correct the error

Here is the complete correction of the error.

Considering the expression

[tex]1-\frac{2}{x-2}=\frac{x+1}{x+2}[/tex]

[tex]\mathrm{Find\:Least\:Common\:Multiplier\:of\:}x-2,\:x+2:\quad \left(x-2\right)\left(x+2\right)[/tex]

[tex]1\cdot \left(x-2\right)\left(x+2\right)-\frac{2}{x-2}\left(x-2\right)\left(x+2\right)=\frac{x+1}{x+2}\left(x-2\right)\left(x+2\right)[/tex]

[tex]\left(x-2\right)\left(x+2\right)-2\left(x+2\right)=\left(x+1\right)\left(x-2\right)[/tex]

[tex]x^2-2x-8=x^2-x-2[/tex]

[tex]x^2-2x-8+8=x^2-x-2+8[/tex]

[tex]x^2-2x=x^2-x+6[/tex]

[tex]-x=6[/tex]

[tex]\frac{-x}{-1}=\frac{6}{-1}[/tex]

[tex]x=-6[/tex]