# How do you find the GCF of 21ab, 35a, 56ab^3?

Mar 14, 2017

$7 a$

#### Explanation:

$21 a b , 35 a , 56 a {b}^{3}$

divided by $a$
$21 b , 35 , 56 {b}^{3}$

divided by $7$
$3 b , 5 , 8 {b}^{3}$

since no more can be divided to the above expressions or number,
therefore it GCF is $a \cdot 7 = 7 a$