Question

Greatest common factor of: 12,90

Answer 1

12                90
1 × 12          1 × 90
2 × 6            2 × 45
3 × 4            3 × 30
                    5 × 18
                   6 × 15
                   9 × 10

GCF = 6

Answer 2

6 because it is the highest and goes into 12 twice and 90 15 times