How do you factor by grouping #3ab - b - 4 + 12a#? Algebra Polynomials and Factoring Factoring by Grouping 1 Answer Phillip E. May 5, 2015 #3ab-b-4+12a = (3a-1)(b+4)# Reorder as #3ab - b +12a-4# This is #b(3a-1) +4(3a-1)# Which is #(3a-1)(b+4)# Answer link Related questions What is Factoring by Grouping? How do you factor by grouping four-term polynomials and trinomials? Why does factoring polynomials by grouping work? How do you factor #2x+2y+ax+ay#? How do you factor #3x^2+8x+4# by using the grouping method? How do you factor #6x^2-9x+10x-15#? How do you group and factor #4jk-8j^2+5k-10j#? What are the factors of #2m^3+3m^2+4m+6#? How do you factor quadratics by using the grouping method? How do you factor #x^4-2x^3+5x-10#? See all questions in Factoring by Grouping Impact of this question 2720 views around the world You can reuse this answer Creative Commons License