Question 44878
{{{4Z^3 - 18Z^2 - 10Z}}}
= {{{2Z(2Z^2 - 9Z - 5)}}}


So we have to factorise {{{2Z^2 - 9Z - 5}}}.


See my solution to the problem mentioned below for more detailed conception of how to solve such problems.
http://www.algebra.com/cgi-bin/jump-to-question.mpl?question=44877


1. 2 x (-5) = -10
2. 1 x (-10) = -10 and -9 = 1 + (-10)
3. Given expression: {{{2Z(2Z^2 + Z - 10Z - 5)}}}.
4. Taking common terms in brackets: {{{2Z(Z(2Z + 1) - 5(2Z + 1))}}}.
5. Re-writing the expression we get the factors: {{{2Z(2Z + 1)(2Z - 5)}}}.