Упростите алгебраическое выражение 12-y/(6y-36)+6/(6y-y2)

\frac{12-y}{6y-36 } + \frac{6}{6y- y^{2} } = \frac{12-y}{6 (y-6)} + \frac{6}{y(6-y)} = \frac{12y- y^{2}-36 }{6y(y-6)} = \frac{-( y^{2} -12y+36)}{6y (y-6)} = \frac{-( y-6)^{2} }{6y (y-6)} = \frac{6-y}{6y}