Math Is Fun Forum

nycguitarguy

Member

Registered: 2024-02-24

Posts: 523

Find GCF

Find the GCF of 45 and 75.

I will start by listing the factors of each.

Factors of 45: 1, 3, 5, 9, 15, 45

Factors of 75: 1, 3, 5, 15, 25, 75

The common factors are 1, 3, 5, and 15.

Which is the biggest? The biggest is 15.

So, the GCF of 45 and 74 is 15.

You say?

Bob

Administrator

Registered: 2010-06-20

Posts: 10,184

Re: Find GCF

I'm happy with your working and final answer.   

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

nycguitarguy

Member

Registered: 2024-02-24

Posts: 523

Re: Find GCF

I'm happy with your working and final answer.   

Bob

Thank you, Bob. I try showing my work when time allows.

amnkb

Member

Registered: 2023-09-19

Posts: 253

Re: Find GCF

Find the GCF of 45 and 75.

Another way is to do the prime factorization w/ a table:

factors
 45: 3 * 3 * 5
 75: 3     * 5 * 5
---+--------------
GCF: 3     * 5    = 15

nycguitarguy

Member

Registered: 2024-02-24

Posts: 523

Re: Find GCF

Find the GCF of 45 and 75.

Another way is to do the prime factorization w/ a table:

factors
 45: 3 * 3 * 5
 75: 3     * 5 * 5
---+--------------
GCF: 3     * 5    = 15

The prime factorization method is cool.