 where <span class="nowrap">S<sub>1</sub></span> = <span class="nowrap">(R<sub>1</sub> - TR<sub>0</sub>)/(60g<sub>1</sub>)</span>,<br>&rArr;&nbsp;&nbsp;mt &equiv; S<sub>1</sub> (mod a).</p><p>This equation can be solved by first considering the equation <span class="nowrap">&mu;t &equiv; 1 (mod a)</span>. Here &mu; is known as the <i>modular multiplicative inverse</i> of t. The modular multiplicative inverse can be calculated using the <i>d&#224; y&#462;n qi&#250; y&#299; sh&#249;</i> (大衍求一術), whi