To solve the equation \( 3(2x - 5) = 6x - 15 \), let's start by distributing the 3 on the left side:
\[ 3 \cdot 2x - 3 \cdot 5 = 6x - 15 \]
This simplifies to:
\[ 6x - 15 = 6x - 15 \]
Now we notice that both sides of the equation are equal. This indicates that the equation holds true for all values of \( x \).
Since both sides are the same, we can conclude that there are infinitely many solutions.
Therefore, the correct response is:
E. infinitely many solutions