Question

do the questions that are circled also GCF stands for greatest common factor

Answer 1

I’m not sure how your class works, but usually if they are circled it means you only have to do the circled ones. GCF always stands for greatest common factor

Answer 2

Depends. The answer to 8 is 1, the answer to 10 is 14, and the answer to 12 is 30.