Question

3x ( x + 1 ) - 2x ( x + 2 ) = - 1 - x 

Answer 1

\(3x\left(x+1\right)-2x\left(x+2\right)=-1-x\\ \Rightarrow3x^2+3x-2x^2-2x+x+1=0\\ \Rightarrow x^2+2x+1=0\\ \Rightarrow\left(x+1\right)^2=0\\ \Rightarrow x+1=0\\ \Rightarrow x=-1\)

Answer 2

\(PT\Leftrightarrow3x^2+3x-2x^2-2x+x+1=0\)

\(\Leftrightarrow x^2+2x+1=0\)

\(\Leftrightarrow\left(x+1\right)^2=0\)

\(\Leftrightarrow x=-1\)

Vậy: ...