How do you factor by grouping # b^2 - 8b + 16 - c^2 #? Algebra Polynomials and Factoring Factoring by Grouping 1 Answer George C. May 17, 2015 #b^2-8b+16-c^2# #= (b^2-8b+16)-c^2# #= (b-4)^2 - c^2# #= ((b-4)+c)((b-4)-c)# #= (b+c-4)(b-c-4)# The factoring of #(b-4)^2 - c^2# as #((b-4)+c)((b-4)-c)# is an instance of the identity: #m^2-n^2=(m+n)(m-n)# with #m=b-4# and #n=c#. 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 2786 views around the world You can reuse this answer Creative Commons License