How do you factor the expressions #112a^2b - 343b #?

1 Answer
Apr 6, 2016

#112a^2b-343b= 7b(4a-7)(4a+7)#

Explanation:

First note that both terms are divisible by #7b#, so separate that out as a factor first. Then use the difference of squares identity:

#A^2-B^2 = (A-B)(A+B)#

with #A=4a# and #b=7# as follows:

#112a^2b-343b#

#= 7b(16a^2-49)#

#= 7b((4a)^2-7^2)#

#= 7b(4a-7)(4a+7)#