First find the factors of each number
Factors of 28: 1,2,4,7, 14, 28
Factors of 77: 1, 7, 11, (you can go further, but there is no point as you have reached the highest COMMON factor)
What is the highest factor COMMON to both - answer - 7
I hope this helps
Factors of 28: 1,2,4,7, 14, 28
Factors of 77: 1, 7, 11, (you can go further, but there is no point as you have reached the highest COMMON factor)
What is the highest factor COMMON to both - answer - 7
I hope this helps