How do you factor #z^3 + 2z^2 - 16z - 32# by grouping?

1 Answer
Jun 13, 2016

Answer:

#(z + 2)(z + 4)(z - 4)#

Explanation:

There are 4 terms, so group them into two group of two - make sure there is a PLUS sign between the groups.

#(z^3 + 2z^2) + (-16z -32) " common factor from each pair"#
=#z^2(z + 2) -16(z + 2)" note -16 as the common factor" #
=#(z+2)(z^2 - 16)#

=#(z + 2)(z + 4)(z - 4)#