What two numbers add up to 18 and subtract to 4?

Let's denote the two numbers as x and y. We can set up a system of equations: x + y = 18 and x - y = 4. By solving this system simultaneously, we can find that x = 11 and y = 7. Therefore, the two numbers that add up to 18 and subtract to 4 are 11 and 7.