Question 66274
Factor:
{{{12m^3-8m^2-15m}}} First, factor out an m.
{{{m(12m^2-8m-15)}}} Now you need to try to factor the parentheses.
{{{12m^2-8m-15}}}
Find the factors of 12.
1X12 = 12
2X6 = 12
3X4 = 12
Now factor the -15.
1X(-15) or (-1)X15 = -15
3X(-5) or (-3)X5 = -15
Let's try:
{{{(12m + 1)(m - 15) = 12m^2 - 180m + m - 15}}} Nope!
{{{(2m + 3)(6m - 5) = 12m^2 -10m + 18m - 15}}} = {{{12m^2 + 8m - 15}}} Almost there!  Lets switch the signs around.
{{{2m - 3)(6m + 5) = 12m^2 + 10m - 18m - 15}}} = {{{12m^2 - 8m - 15}}} That's it!..So, putting it all together:
{{{12m^3 - 8m^2 - 15m = m(2m - 3)(6m + 5)}}}