slope form is y/x
to find this subtract -5, 7 by -3, 5 to get
-2, 2 and putting it in slope format....2/-2 which would be -1 or just -x (means -1x)
so far we've found out.....y = -x (+b)
b is what we need to find now so... plug in one of the coordinates
7=5+b (5 because --5 is positive 5)
b=2
so FINALLY the equation would be y = -x + 2