Question 72235
<pre>
{{{(3x+15)/(3x^2+ 24x+45)}}}

             3x + 15
        _______________      note: 3x^2 + 24x + 45 &#8800; 0
        3x^2 + 24x + 45 


           3(x + 5)
       ________________    (3x + 9) (x + 5)&#8800; 0
       (3x + 9) (x + 5) 


           {{{cross(3)}}} {{{cross(x + 5)}}}
       ________________              restrictions  x = -5
       {{{cross(3)}}}(x + 3){{{cross(x + 5)}}}                          x = -3

           
              1
           ________
            x + 3