your equation: x^-4xy+3y^ now figure out what adds to -4 and multiplied to +3 (-3&-1) use that information to factor. you get: (x-3y)(x-y) now use the distributive property to make sure it's the right answer: x^-xy-3xy+3y^ this means (x-3y)(x-y) is correct. hope this helped :)