SOLUTION: Hi, I need help solving this problem on reducing rational expressions: {{{((a^2-4ab+4b^2)-z^2)/(5a-10b+5z)}}} Thanks!

Factor the  as  which
can be written as . So now we have



Now the numerator is the difference of two squares, 
which factors as
[][] or
[][] or
.  So now we have:



Now we factor the denominator simply by taking out 5, and so
we now have



Now we can cancel the 's and all that's left is



Edwin