3m-3d 3m-2d -------- -- --------- Упростите выражение 2m-2d m-3d

$\frac{3m - 3d}{2m-2d} - (- \frac{3m-2d}{m-3d} ) = \frac{3(m-d)}{2(m-d)} + \frac{3m-2d}{m-3d} = \frac{3}{2} +\frac{3m-2d}{m-3d} = \\ \\ = \frac{3(m-3d)+2(3m-2d)}{2(m-3d)} = \frac{3m-9d+6m-4d}{2(m-3d)} = \frac{9m-13d}{2m-6d}$
Если "--" опечатка и выражение следует читать так:
$\frac{3m - 3d}{2m-2d} - \frac{3m-2d}{m-3d} = \frac{3(m-d)}{2(m-d)} - \frac{3m-2d}{m-3d}= \frac{3}{2} -\frac{3m-2d}{m-3d}= \\ \\ = \frac{3*(m-3d) -2(3m-2d)}{2(m-3d)}= \frac{3m-9d-6m+4d}{2(m-3d)} = \frac{5d-3m}{2m-6d}$