324:(x+12)=9

To solve the equation \( 324:(x+12) = 9 \), we can rewrite it in a more typical mathematical format:

\[ \frac{324}{x + 12} = 9 \]

Next, we will eliminate the fraction by multiplying both sides of the equation by \( x + 12 \):

\[ 324 = 9(x + 12) \]

Now, distribute the 9 on the right side:

\[ 324 = 9x + 108 \]

Next, isolate the term with \( x \) by subtracting 108 from both sides:

\[ 324 - 108 = 9x \]

\[ 216 = 9x \]

Now, divide both sides by 9 to solve for \( x \):

\[ x = \frac{216}{9} \]

\[ x = 24 \]

So, the solution is:

\[ \boxed{24} \]