Сократите дробь (1+4x-4y)/(4y^2-4x^2-y-x)
4y^2-4x^2-y-x=4*(y^2-x^2)-(y+x)= =4*(y-x)*(y+x)-(y+x)= =(y+x)*(4y-4x-1) (1+4x-4y)/(4y^2-4x^2-y-x)= =(1+4x-4y)/((y+x)*(4y-4x-1))= =-(4y-4x-1)/((y+x)*(4y-4x-1))=-1/(y+x)