How do you factor #6m ^ { 3} - 18m ^ { 2} - 240m?#

2 Answers
May 2, 2018

#6m(m-8)(m+5)#

Explanation:

#"take out a "color(blue)"common factor "6m#

#=6m(m^2-3m-40)#

#"the factors of - 40 which sum to - 3 are - 8 and + 5"#

#=6m(m-8)(m+5)#

May 2, 2018

#(6m)(m-8)(m+5)#

Explanation:

First, notice all terms have #m#, so that can be factored out:
#6m^3-18m^2-240m#
#=m(6m^2-18m-240)#
#6#, #18#, and #240# These numbers' GCF is #6#, so we can factor that out aswell:
#=6m(m^2-3m-40)# Now we can factor the parentheses:
#m^2-3m-40#
Factors of 40:
#1,40#
#2,20#
#4,10#
#5,8#
#5# and #8# can be subtracted to get #-3#, so these are the factors:
#(m-8)(m+5)# Putting it in the entire expression:
#(6m)(m-8)(m+5)#