How do you multiply #(3m+1)(m-4)(m+5)#?

1 Answer
Nov 12, 2014

#(3m+1)(m-4)(m+5)#

by distributing #(m-4)# to #3m# and #1#,

#=[3m(m-4)+1(m-4)] (m+5)#

by distributing #3m#,

#=(3m^2-12m+m-4)(m+5)#

by collecting like terms,

#=(3m^2-11m-4)(m+5)#

by distributing #(m+5)#,

#=3m^2(m+5)-11m(m+5)-4(m+5)#

by distributing #3m^2#, #-11m#, and #-4#,

#=3m^3+15m^2-11m^2-55m-4m-20#

by collecting like terms,

#=3m^3+4m^2-59m-20#


I hope that this was helpful.