what is the GCF of 42, 63, and 105?

3 ⤊

what is the GCF of 42, 63, and 105?

is anyone doesnt know GCF means greatest common factor

2007-11-26 08:00:40 · 3 answers · asked by RiSSYDOLL<3 2 in Science & Mathematics ➔ Mathematics

3 answers

As I looked at this problem, I saw one thing off the top.

4+2 = 6
6+3 = 9
1+0+5 = 6

This means all three are divisible by 3 (A fun math trick to know and share)

42/3 = 14
63/3 = 21
105/3 = 35

14, 21, and 35 are all multiples of 7

14/7 = 2
21/7 = 3
35/7 = 5

2, 3 and 5 are all relatively prime.

Therefore, we were able to divide each number by 3 and 7. So, the GCF is 3x7 = 21.

2007-11-26 08:06:20 · answer #1 · answered by lhvinny 7 · 3⤊ 0⤋

4 12 18 5 7

2016-05-26 00:51:21 · answer #2 · answered by marti 3 · 0⤊ 0⤋

7 because 7x6=42 7x9=63 7x15=105

2007-11-26 08:04:45 · answer #3 · answered by Darkstar667 3 · 0⤊ 4⤋