Answer: b. 18
Explanation:
You have to follow the order of operations: (), exponents, */, -+, left to right.
18 − 12 + 2 × 3² − 12 ÷ (1 + 1)
First, the parentheses:
18 − 12 + 2 × 3² − 12 ÷ 2
Second, the exponent:
18 − 12 + 2 × 9 − 12 ÷ 2
Third, the multiplication and division, starting from the left:
18 − 12 + 18 − 12 ÷ 2
18 − 12 + 18 − 6
Finally, the addition and subtraction from left to right:
6 + 18 - 6
24 - 6
18