To find slope use the formula M = y2 - y1 
 -----------
 x2 - y1 
say you were given this (2,3) (-4,5) 2 would be x1 and 3 would be y1, -4 would be x2 and 5 would be y2 then just put it into the formula 5 - 3
 --------
 -4 - 2
which would be 2/ -6 which would simplify to 1/3