Question 670801
m = (y2 - y1)/(x2 - x1)


3/2 = (a - 9)/(3-5)


3/2 = (a - 9)/(-2)


3*(-2) = 2(a - 9)


-6 = 2(a - 9)


-6/2 = a - 9


-3 = a - 9


a - 9 = -3


I'll let you finish.