Provide your best answer for the following math problem. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The problem is: if 50 % of x equals the sum of y and 20 , then what is the value of x – 2 y ?
40
x = 2(y + 20)/0.5