Question 631776
  <pre><font face = "Tohoma" size = 3 color = "indigo"><b> 
Hi,
{{{(2z-1)/ (z^2+z-6) - (3z-5)/ (z^2-2z-15) + (2z-3)/ (z^2-7z+10) }}}
much like one like this {{{z/2 - (z-1)/5 + (2z+1)/3}}} 1st step is to find the Lowest Common Denominator
Exploring the Denominators and factoring them:
(z^2+z-6)   &#8658; (z+3)(z-2)
(z^2-2z-15) &#8658; (z-5)(z+3)
(z^2-7z+10) &#8658; (z-5)(z-2)
LCD is (z+3)(z-2)(z-5)
{{{((2z-1)(z-5) - (3z-5)(z-2) + (2z-3)(z-3))/((z+3)(z-2)(z-5)) }}}
 Simplify the Numerator and Your done.