Ответ:

Объяснение:

а) x -x/(x+1)=(x²+x-x)/(x+1)=x²/(x+1)

б) (m+2)/(4m) -1/(m+4)=((m+2)(m+4)-4m)/(4m(m+4))=(m²+4m+2m+8-4m)/(4m(m+4))=(m²+2m+8)/(4m(m+4))

в) x/(x+y) +y/(x-y)=(x²-xy+xy+y²)/((x-y)(x+y))=(x²+y²)/(x²-y²)

г) (3x+y)/(x²+xy) -(x+3y)/(y²+xy)=(3x+y)/(x(x+y)) -(x+3y)/(y(x+y))=(3xy+y²-x²-3xy)/(xy(x+y))=(y²-x²)/(xy(x+y))=((y-x)(y+x))/(xy(x+y))=(-x+y)/(xy)