What is the greatest common factor of 42 and 91?

What is the greatest common factor of 42 and 91?

Seven, because six times seven equals 42
13 times 7 = 91
Also 6 and 13 have no common factor
So the greatest common factor of 42 and 91 is 7

The greatest common divisor of 91 and 49 is______ ．

∵ 91 = 49 × 1 + 42, 49 = 42 × 1 + 7, 42 = 7 × 6. The greatest common divisor of 91 and 49 is 7

Find out the greatest common factors 17,34,26,39,48,56,8,9,1,100 of the following groups

The greatest common factor of 17 and 34 is 17
The greatest common factor of 26 and 39 is 13
The greatest common factor of 48 and 56 is 8
8. The greatest common factor of 9 is 1
1. The greatest common factor of 100 is 1

Decompose the following prime factors by short division: 48 56 64 72 86 111

48=2×2×2×2×3
56=2×2×2×7
64=2×2×2×2×2×2
72=2×2×2×3×3
86=2×43
111=3×37