X :6=45-(18+12)

Let's solve the equation step by step.

We start with the equation:

\[ X : 6 = 45 - (18 + 12) \]

First, calculate the expression inside the parentheses:

\[ 18 + 12 = 30 \]

Now substitute that back into the equation:

\[ X : 6 = 45 - 30 \]

Next, perform the subtraction:

\[ 45 - 30 = 15 \]

Now we have:

\[ X : 6 = 15 \]

To isolate \( X \), multiply both sides by 6:

\[ X = 15 \times 6 \]

Now calculate \( 15 \times 6 \):

\[ X = 90 \]

So, the solution for \( X \) is:

\[ X = 90 \]