x-y - 3x^2 + 3y^2 = (3y^2-y) - (3x^2-x) = y (3y-1) - x (3x-1) = (y-x) * (3y+3x-1)

Ответ:

(x-y)(-3x-3y+1)

Объяснение:

x-y-3x^2+3y^2

x-y-3(x^2-y^2)

x-y-3(x-y)(x+y)

(x-y)(-3(x+y)+1)

(x-y)(-3x-3y+1)