Science Bowl Question

W) y' + y = 0 [y prime plus y equals zero]

X) y'' - 2y² - 2 = 0 [y double prime minus 2y squared minus 2 equals zero]

Y) y' - xy = 0 [y prime minus xy equals zero]

Z) y' - 2y² - 2 = 0 [y prime minus 2y squared minus two equals zero]