Решите систему уравнений: xy/x+y= 5 { xz/x+z = 7 yz/y+z = 9 Помогите СРОЧНО!!!! / - дробь

Вот накалякал. Разбирайся :)xy/(x+y) = 5 xz/(x+z) = 7 yz/(y+z) = 9===========xy = 5x + 5y xz = 7x + 7z yz = 9y + 9z===========x(y-5) = 5y x = 5y/(y-5)----- 5yz/(y-5) = 35y/(y-5) + 7z 5yz = 35y + 7z * (y-5) 5yz = 35y + 7yz - 35z 2yz + 35y = 35z y(2z + 35) = 35z y = 35z/(2z + 35) = z/(2z/35 + 1)------35z^2/(2z + 35) = 315z/(2z + 35) + 9z 35z^2 = 315z + 9z*(2z + 35) 35z^2 = 315z + 18z^2 + 315z 17z^2 = 630z z=630/17-------y = 35*630/(2*630/17 + 35)/17 = 35*630/(1260 + 595) = 22050/1855 = 630 / 53x = 5*630/(630/53 - 5)/53  =  5*630/((630/53 - 5)*53) = 5*630/365 = 630/73