Answer:

Step-by-step explanation:
We are asked to find the GCF of
and
.
The greatest common factor of numerical part would be GCF of 28 and 16.
Factors of 28: 1, 2, 4, 7, 14, 28.
Factors of 16: 1, 2, 4, 8, 16.
The greatest common factor of 28 and 16 is 4.
The GCF of variable part:


The greatest common factor of
and
is
.
Upon combining the GCF of numerical part and algebraic part, we will get:
Therefore, the greatest common factor of both expressions is
.