data/mathematical/40.mml
<math xmlns='http://www.w3.org/1998/Math/MathML' display='inline'><semantics><mrow><mtext> </mtext><mo stretchy="false">[</mo><mi>A</mi><msub><mo stretchy="false">]</mo> <mi>t</mi></msub><mo>=</mo><mo>−</mo><mi>k</mi><mi>t</mi><mo>+</mo><mo stretchy="false">[</mo><mi>A</mi><msub><mo stretchy="false">]</mo> <mn>0</mn></msub></mrow><annotation encoding='application/x-tex'>\ [A]_t = -kt + [A]_0</annotation></semantics></math>