How to factor 32x^2-2y^2

The greatest common factor of 32x^-2y^2 is 2 (there is o common variable and both 32 and 2 divide by 2)

Thus, divide each term by 2

32x^2/2 = 16x^2

-2y^2 = - 1y^2 = - y^2

Thus, your answer is

2 (16x^2-y^2)