Let's simplify the given expression step by step:

\[ (3x - 15) - 2 \times (x - 5) \]

First, distribute the \(-2\) through the parentheses:

\[ (3x - 15) - 2(x - 5) \]
\[ (3x - 15) - 2x + 10 \]

Next, combine like terms:

\[ 3x - 2x - 15 + 10 \]

Simplify the expression:

\[ x - 5 \]

So, the simplified form of the given expression is:

\[ x - 5 \]