mml=<math xmlns="http://www.w3.org/1998/Math/MathML"><mo>&#x2206;</mo><mo>=</mo><mfrac><mn>1</mn><mn>2</mn></mfrac><mfenced open="{" close="}" separators="|"><mrow><msub><mi mathvariant="normal">x</mi><mn>1</mn></msub><mfenced separators="|"><mrow><msub><mi mathvariant="normal">y</mi><mn>2</mn></msub><mo>-</mo><msub><mi mathvariant="normal">y</mi><mn>3</mn></msub></mrow></mfenced><mo>+</mo><msub><mi mathvariant="normal">x</mi><mn>2</mn></msub><mfenced separators="|"><mrow><msub><mi mathvariant="normal">y</mi><mn>3</mn></msub><mo>-</mo><msub><mi mathvariant="normal">y</mi><mn>1</mn></msub></mrow></mfenced><mo>+</mo><msub><mi mathvariant="normal">x</mi><mn>3</mn></msub><mo>(</mo><msub><mi mathvariant="normal">y</mi><mn>1</mn></msub><mo>-</mo><msub><mi mathvariant="normal">y</mi><mn>2</mn></msub><mo>)</mo></mrow></mfenced><mspace linebreak="newline"/><mo>=</mo><mfrac><mn>1</mn><mn>2</mn></mfrac><mfenced open="{" close="}" separators="|"><mrow><mn>3</mn><mfenced separators="|"><mrow><mn>2</mn><mo>+</mo><mn>1</mn></mrow></mfenced><mo>+</mo><mfenced separators="|"><mrow><mo>-</mo><mn>4</mn></mrow></mfenced><mfenced separators="|"><mrow><mo>-</mo><mn>1</mn><mo>-</mo><mn>8</mn></mrow></mfenced><mo>+</mo><mn>5</mn><mfenced separators="|"><mrow><mn>8</mn><mo>-</mo><mn>2</mn></mrow></mfenced></mrow></mfenced><mspace linebreak="newline"/><mo>=</mo><mfrac><mn>1</mn><mn>2</mn></mfrac><mfenced open="{" close="}" separators="|"><mrow><mn>9</mn><mo>+</mo><mn>36</mn><mo>+</mo><mn>30</mn></mrow></mfenced><mo>=</mo><mfrac><mn>75</mn><mn>2</mn></mfrac><mo>=</mo><mn>37</mn><mfrac><mn>1</mn><mn>2</mn></mfrac><mi>sq</mi><mi mathvariant="normal">&#xA0;</mi><mi>unit</mi></math>