Answer: C. Their slopes are negative reciprocals
Step-by-step explanation:
The slopes of two perpendicular lines are negative reciprocals of each other.
Pemdas
Parentheses none
Exponents none
Multiplication 18 multiplied by 2 is 36
Division 36 divided by 4 is 9
Addition none
Subtraction 9 minus 36 is -27
Your answer is -27