Answer:
-51
Step-by-step explanation:
Step 1: Solve inside the parenthesis
12 + 3(18 - 42) + 9
12 + 3(-24) + 9
Step 2: Multiply
12 + 3(-24) + 9
12 - 72 + 9
Step 3: Combine the first two numbers
(12 - 72) + 9
-60 + 9
Step 4: Combine the last two numbers
-60 + 9
-51
Answer: -51
