16a^4b^4 + 32a^3b^5 - 48a^2b^6the GCF would be : 16a^2b^4....because the 16 is the highest coefficient that goes into 16,32,and 48. Then u just take the a with the smallest exponent and the b with the smallest exponent.
16a^{2} b^{4} (a-b)(a+3b)------> 16a^{2} b^{4}
Hope I Helped!!!