Amsmath

• How to Bold Math Symbols in LaTeX
  Use \mathbf for upright Latin letters, \boldsymbol for bold math symbols, or the bm package for reliable bolding of Greek letters and operators.
• Can You Use align* Inside enumerate* in LaTeX?
  The reason align* fails inside enumitem’s enumerate* is that one is display math and the other an inline list. Use regular enumerate for equations.
• How to Automatically Size Parentheses Across Multiple LaTeX Lines
  Put a multiline expression in an aligned block inside one automatic delimiter pair; use fixed-size delimiters if the rows must stay separate.