Question 347325
Simplify 6-w/w-3 x 3w-7/3-w 
 You said subtract so assume the problem is:
{{{((6-w))/((w-3))}}} - {{{((3w-7))/((3-w))}}}
:
We can factor out -1 from the 2nd denominator, we have
{{{((6-w))/((w-3))}}} - {{{((3w-7))/(-1(w-3))}}}
Which is
{{{((6-w))/((w-3))}}} - {{{(-(3w-7))/((w-3))}}}; Both denominators are the same
Minus a minus is a plus 
{{{((6-w))/((w-3))}}} + {{{((3w-7))/((w-3))}}} = {{{((6-w+3w-7))/((w-3))}}} = {{{((2w-1))/((w-3))}}}