To solve the equation \( 15w + 3w + 19 = -17 \), we first combine like terms:
\[ 15w + 3w = 18w \]
So the equation becomes:
\[ 18w + 19 = -17 \]
Next, we isolate \( 18w \) by subtracting \( 19 \) from both sides:
\[ 18w + 19 - 19 = -17 - 19 \]
This simplifies to:
\[ 18w = -36 \]
Now, we solve for \( w \) by dividing both sides by \( 18 \):
\[ w = \frac{-36}{18} = -2 \]
Thus, the solution is:
\[ \boxed{w = -2} \]