To solve the equation \( 9x - 6 = 12 \) after Marion adds 6 to both sides, the equation becomes:
\[ 9x - 6 + 6 = 12 + 6 \]
which simplifies to:
\[ 9x = 18 \]
In the next step, Marion needs to isolate \( x \). To do this, she can divide both sides of the equation by 9:
\[ \frac{9x}{9} = \frac{18}{9} \]
This simplifies to:
\[ x = 2 \]
So, in the next step, each side needs to be divided by 9.