To factor the expression \(6c + 42d\), we first need to identify the greatest common factor (GCF) of the coefficients 6 and 42.
The GCF of 6 and 42 is 6. We can factor out 6 from both terms:
\[ 6c + 42d = 6(c + 7d) \]
So, the factored expression is:
\[ 6(c + 7d) \]
This is written as a product with a whole number greater than 1.