Question 746863
First find the gradient  => y2 - y1/ x2 - x1
                         = 11 - 5/ 4 - 1
                         = 6/3
                         = 2 = m
Next use y - b = m(x - a)
   Taking one of your points (1,5)

         y - 5 = 2(x - 1)
             y = 2x - 2 + 5
             y = 2x + 3