Answer: 18.
Step-by-step explanation: Substitute x for 4 and y for 2. This gives us 5*4 - 4/2. Using the order of operations, we begin with Multiplication. This gives us 20 - 4/2. Then, we do Division. This gives us 20 - 2. Next, Subtraction. 20 - 2 = 18. Our answer is 18.