The factor of the expression is 
Explanation:
The given expression is 
We need to determine the factor of the expression.
The factor of the expression can be determined by simplifying the given expression.
Now, we shall rewrite each term as a multiple of 7.
Thus, rewriting, we have,



Hence, substituting these values in the expression, we get,

Let us factor out the common term 7, we get,

Thus, the factor of the expression is 
The factor of the expression is determined by taking out the common term 7 from the expression.