Here is a factor tree of 39: 39 3 x 13 Since these are prime numbers, the factor tree is finished. The prime factors of 39 are 3 and 13.
39 3,13
39 3,13
39 3,13
39 = 3 * 13
39 3,13
39 13,3 3 x 13 = 39
The factors of 39 are 1, 3, 13 and 39.
78 6 x 13 (2x3) x 13 The numbers 2, 3, and 13 are prime numbers, so the factor tree is complete. An alternate version of a factor tree for 78 is: 78 2 x 39 2 x (3x13)
195 5, 39 5, 3, 13
Factor tree: ............78 .........../..\ ..........2..39 ............../..\ ............3...13 78 = 2 x 3 x 13
3 * 13 (both prime numbers)