To simplify the expression \(6(3x−5)+2(3x−5)−8(3x−5)\), we can combine like terms.
First, notice that \( (3x - 5) \) is a common factor in all the terms:
\[ 6(3x - 5) + 2(3x - 5) - 8(3x - 5) \]
We can factor out \( (3x - 5) \):
\[ (3x - 5)(6 + 2 - 8) \]
Now simplify the expression inside the parentheses:
\[ 6 + 2 - 8 = 8 - 8 = 0 \]
So, now we have:
\[ (3x - 5)(0) = 0 \]
Thus, the simplified expression is:
\[ \boxed{0} \]