mml=<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>tan</mi><mo>&#x2061;</mo><mfenced separators="|"><mrow><mn>3</mn><mi mathvariant="normal">x</mi><mo>-</mo><mn>2</mn><mi mathvariant="normal">x</mi></mrow></mfenced><mo>=</mo><mi mathvariant="normal">&#xA0;</mi><mi>tan</mi><mo>&#x2061;</mo><mi mathvariant="normal">x</mi><mo>=</mo><mi mathvariant="normal">&#xA0;</mi><mn>1</mn><mi mathvariant="normal">&#xA0;</mi><mo>&#x21D2;</mo><mi mathvariant="normal">x</mi><mo>=</mo><mi mathvariant="normal">&#xA0;</mi><mi>n&#x3C0;</mi><mo>+</mo><mfrac><mi mathvariant="normal">&#x3C0;</mi><mn>4</mn></mfrac></math>