Maximize 2X1 + 5X2

subject to X1 + X2 <= 15

-X1 + X2 <= 2

X1 - X2 >= 2

X1 + X2 >= 2

X1, X2 >= 0 and integer

I am supposed to convert the model to binary. I'm thinking of using a Xij format, though I am not really sure how to constrain it. Any ideas? Thank you.