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 2954 views around the world You can reuse this answer Creative Commons License