What is the greatest common factor of 18 24 and 42?

Answer 1

OK. here's how you do this.

so, do you know how to find the prime factorization of a number,( get it down to the smallest prime numbers that multipy together to make that number?) a factor tree is an easy way to do this.

just take the number, think of two numbers that multipy to get your number, and go from there(i like to use something easy like 2, i f possible, to start-its easy and since its prime you dont have to do much more with it.)

18

2 x 9 so the prime factorization of 18 is 2x3x3.

3x3

then take 24.

24

2x 12

2x6 so the prime factorization of 24 is 2x2x2x3.

2x3

then 42.

42

2x21 the prime factorization of 42 is 2x3x7.

3x7

then, once you've done this, you compare them and take the numbers common to all of them.

18..............2 x 3 x 3

24.............2 x 2 x 2 x 3

42.............2 x 3 x 7

all of them have one two and one three in common, so you take 2x3, which makes 6 so the GCF is 6.

(if you have numbers with more than one of the same number, like all have two 2s or something, then you take two, like have you lerned how to factor polynomials yet? prob. not but when you do you will see the connection.)

hope i helped!!!!!!!!!!!

~jaimelefrancais<3
The GCF is 6.
The GCF is 6.
The GCF is 6.