7 -y
_____
Y - 7
Does this factor to 1????
Assuming that the two Ys (y and Y) indicate the same unknown, it would be -1.
(7 - Y)/(Y - 7) = -1(Y - 7)/(Y - 7)
The (Y - 7) terms cancel each other out, leaving -1.
I hope this helps. Thanks for asking.