If A={x:x is a multiple of 3, `x lt 12}` and B={x: `x in N, x^(2)-9x+18=0}` then find A-B.

Explanation

To solve the problem, we need to find the sets A and B as defined in the question and then compute the difference A - B.

### Step 1: Define Set A
Set A is defined as:
\[ A = \{ x : x \text{ is a multiple of 3, } x < 12 \} \]

To find the elements of set A, we list the multiples of 3 that are less than 12:
- The multiples of 3 are: 3, 6, 9, 12, 15, ...
...