Solve $LaTeX: \displaystyle | 13 x + 1 |=129$

Splitting into two linear equations gives $LaTeX: \displaystyle 13 x + 1=-129$ and $LaTeX: \displaystyle 13 x + 1=129$ . Solving gives the two solutions $LaTeX: \displaystyle x=\frac{128}{13}$ and $LaTeX: \displaystyle x=-10$