(1/X ) - (10/X^2 - 5X) = X - 3 / 5 - X
X - 5 - 10 = - X * ( X - 3 )
-------------------------------------
X ≠ 0
X ≠ 5
----------------------------------
X - 15 = - X^2 + 3X
X^2 + X - 3X - 15 = 0
X^2 - 2X - 15 = 0
D = 4 + 60 = 64 ; √ D = 8
X1 = ( 2 + 8 ) : 2 = 5
X2 = ( 2 - 8) : 2 = ( - 3 )
--------------------------------
Ответ Х = ( - 3 )