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  <ul class="dropdown-menu" aria-labelledby="dropdown-articles"><li><a class="dropdown-item" href="../articles/a1-det-ex1.html">1. Properties of determinants</a></li>
    <li><a class="dropdown-item" href="../articles/a2-det-ex2.html">2. Evaluation of determinants</a></li>
    <li><a class="dropdown-item" href="../articles/a3-inv-ex1.html">3. Inverse of a matrix</a></li>
    <li><a class="dropdown-item" href="../articles/a4-inv-ex2.html">4. Matrix inversion by elementary row operations</a></li>
    