Let's solve the expression step by step, following the order of operations (PEMDAS):

PEMDAS:

1. Parentheses
2. Exponents
3. Multiplication and Division (from left to right)
4. Addition and Subtraction (from left to right)

The given expression is:

$9 - 18 + \frac{15}{3} \times 6 + 12$

Step 1: Perform Division and Multiplication first

$\frac{15}{3} = 5$ Now the expression becomes: $9 - 18 + 5 \times 6 + 12$ Next, do the multiplication: $5 \times 6 = 30$ So the expression is now: $9 - 18 + 30 + 12$

Step 2: Perform Addition and Subtraction (left to right)

$9 - 18 = -9$ Now: $-9 + 30 = 21$ And: $21 + 12 = 33$

Final Answer:

$33$

Would you like more details, or have any questions?

Here are 5 related questions for practice:

1. Simplify $10 + 24 \div 6 \times 4 - 5$.
2. Solve $20 - 8 + 16 \div 4 \times 3$.
3. Simplify $14 \times 3 - 12 + 36 \div 6$.
4. Evaluate $100 \div 5 + 6 \times 2 - 12$.
5. Simplify $45 \div 9 + 30 - 15 \times 2$.

Tip: Always remember to perform multiplication and division before addition and subtraction in a left-to-right sequence!