What is the GCF of 18a, 20ab and 6ab?

Jun 28, 2018

$2 a$

Explanation:

Given the set: $18 a , 20 a b , 6 a b$.

First find the greatest common factor of $18 , 20 , 6$.

$18 = 2 \cdot {3}^{2}$

$20 = {2}^{2} \cdot 5$

$6 = 2 \cdot 3$

$\therefore \setminus \text{GCF} = 2$

Then, find the $\text{GCF}$ of $a , a b , a b$.

$a = a$

$a b = a \cdot b$

$\therefore \setminus \text{GCF} = a$

Now, multiply the two $\text{GCF}$s of the two sets together.

$2 \cdot a = 2 a$

That is the greatest common factor of the whole sequence.

Jun 28, 2018

G C F is $\textcolor{g r e e n}{2 a}$

Explanation:

G C F is the greatest common factor which finds place in all the terms.

$18 a , 20 a b , 6 a b$

$\implies 9 \cdot \textcolor{g r e e n}{2 a} , 10 b \cdot \textcolor{g r e e n}{2 a} , 3 b \cdot \textcolor{g r e e n}{2 a}$

$2 a$ is common in all the three terms.

Hence the G C F is $\textcolor{g r e e n}{2 a}$