<p class="noindent">  
  A quadratic equation  
     <span class="math">a{x}^{2} + bx + c = 0</span>  
  with  
     <span class="math">a\mathrel{&#x2260;}0</span>  
  has the following solution.  
</p>  
<div class="math">  
     x ={  &#x2212;b &#x00B1;\sqrt{{b}^{2 } &#x2212; 4ac}  
         \over 2a}  
</div>

<p class="noindent">  
  A quadratic equation  
     <span class="math">a{x}^{2} + bx + c = 0</span>  
  with  
     <span class="math">a\ne 0</span>  
  has the following solution.  
</p>  
<div class="math">  
     x =\frac{ -b\pm \sqrt{{b}^{2 } - 4ac} }{2a}  
</div>