To factor the expression \( 35s - 28t - 35u \), we first look for the greatest common factor (GCF) of the coefficients \( 35 \), \( -28 \), and \( -35 \).
The GCF of \( 35 \), \( 28 \), and \( 35 \) is \( 7 \).
Now, we can factor out \( 7 \) from the expression:
\[ 35s - 28t - 35u = 7(5s - 4t - 5u) \]
So, the factored form of the expression is:
\[ 7(5s - 4t - 5u) \]
Here, \( 7 \) is a whole number greater than \( 1 \).