Example: 30 and 42
Factor them.
2 x 3 x 5 = 30
2 x 3 x 7 = 42
Select the common factors.
2 x 3 = 6, the GCF
The factors of 28 are 1,2,4,7,14 and 28. "Common" means "same for both". For these factors to be common, they need to be compared to the factors of another number.
1,3,7,9,21,63 1,2,3,4,8,9,18,24,36,72 The factors in common are 1,3,9 The largest (greatest) common factor is 9
Multiplying the highest prime factors it is: 72
Common factors of 20 are; 1,2,4,5, and 20. 1x20=20, 2x10=20, 4x5=20, 5x4=20, 20x1+=20. If you have to show your work then just check mine.The factors of 20 are 1,2,4,5,10 and 20. For them to be common, they have to be compared to another set of factors.
List the factors. 1,7 1,2,4,5,10,20 The only, and therefore the greatest common factor is 1.
1, 5, 19, 95 There's no work to show.
where is it
The factors of 15 are:1, 3, 5, 15The factors of 305 are:1, 5, 61, 305The GCF is 5.
Since 8 is a factor of 16, all of its factors are common.
Since they have no common prime factors, multiply them together.3 x 7 x 10 = 210, the LCM
The factors of 91 are 1, 7, 13, 91 For them to be common, they need to be compared to another set of factors.
The factors of 24 are: 1, 2, 3, 4, 6, 8, 12, 24 The factors of 64 are: 1, 2, 4, 8, 16, 32, 64 The factors of 88 are: 1, 2, 4, 8, 11, 22, 44, 88 The common factors are: 1, 2, 4, 8