\[x^{2} - 3|x + 1| + 2x \leq - 1\]
\[x^{2} + 2x + 1 \leq 3|x + 1|\]
\[(x + 1)^{2} \leq 3|x + 1|\]
\[y = |x + 1|:\]
\[y^{2} \leq 3y\]
\[y^{2} - 3y \leq 0\]
\[y(y - 3) \leq 0\]
\[0 \leq y \leq 3.\]
\[0 \leq |x + 1| \leq 3\]
\[0 \leq |x + 1| - при\ всех\ \text{x.}\]
\[|x + 1| \leq 3\]
\[- 3 \leq x + 1 \leq 3\]
\[- 4 \leq x \leq 2\]
\[Ответ:x \in \lbrack - 4;2\rbrack.\]