а) x²+x-x/x+1 = x²/x+1
б) (m+2)(m+4)-4m/4m(m+4) = m²+4m+2m+8-4m/4m(m+4) = m²+2m+8/4m(m+4)
в) x²-xy+xy+y²/(x+y)(x-y) = x²+y²/(x+y)(x-y)
г) 3xy²+3x²y+y³+xy²-x³-x²y-3x²y-3xy² / (x²+xy)(y²+xy)=y³+xy²-x³-x²ý / (x²+xy)(y²+xy)
