To factor the expression \( 5m - 15(m - 3) \), we first distribute the \( -15 \) into the parentheses:
\[ 5m - 15(m - 3) = 5m - 15m + 45 \]
Now combine the like terms:
\[ 5m - 15m = -10m \] Thus,
\[ -10m + 45 \]
Now, we can factor out \(-5\) from both terms:
\[ -5(2m - 9) \]
So, the factored form of the expression \( 5m - 15(m - 3) \) is:
\[ -5(2m - 9) \]