3+217x=-8x-42

To solve the equation \( 3 + 217x = -8x - 42 \), we first want to get all the terms involving \( x \) on one side and the constant terms on the other side.

1. Start by adding \( 8x \) to both sides to combine the \( x \) terms:

   \[ 3 + 217x + 8x = -42 \]

   This simplifies to:

   \[ 3 + 225x = -42 \]

2. Next, subtract \( 3 \) from both sides to isolate the \( x \) term:

   \[ 225x = -42 - 3 \]

   Simplifying the right side gives:

   \[ 225x = -45 \]

3. Finally, divide both sides by \( 225 \) to solve for \( x \):

   \[ x = \frac{-45}{225} \]

4. Simplifying \( \frac{-45}{225} \):

   \[ x = \frac{-1}{5} \]

Thus, the solution to the equation \( 3 + 217x = -8x - 42 \) is

\[ \boxed{-\frac{1}{5}} \]