<p>Simplify :</p>
<p> <span class="math-editor mathquill-rendered-math"><span class="fraction non-leaf"><span class="numerator"><span class="roman font"><var>a</var></span><sup class="non-leaf">4</sup><span class="binary-operator">−</span>8<var>a</var></span><span class="denominator">2<var>a</var>²<span class="binary-operator">+</span>5<var>a</var><span class="binary-operator">−</span>3</span><span style="display: inline-block; width: 0;"> </span></span><span class="binary-operator">×</span><span class="fraction non-leaf"><span class="numerator">2<var>a</var><span class="binary-operator">−</span>1</span><span class="denominator"><var>a</var>²</span><span style="display: inline-block; width: 0;"> </span></span><span class="binary-operator">+</span>2<var>a</var><span class="binary-operator">+</span>4<span class="binary-operator">÷</span><span class="fraction non-leaf"><span class="numerator"><var>a</var>²<span class="binary-operator">−</span>2<var>a</var></span><span class="denominator"><var>a</var><span class="binary-operator">+</span>3</span><span style="display: inline-block; width: 0;"> </span></span></span> </p>