5/6*z-z=z/3+1/5 уравнение
5/6z - z = z/3 + 1/5 - 1/6z - z/3 = 1/5 ( - z - 2z )/6 = 1/5 - 1/2z = 1/5 z = 1/5 : ( - 1/2 ) z = - 2/5 z = - 0,4