ystem, points (2,9) and (-1,0) lie on line k. 5 on line k, what is the value of n? (n.21) y = mx + b y = 3x + b (2,9) 9-3(2) + b = 3 y = 3x +3 X slope Y-Y X₂-X How do you get to 3 here? I see 3x9=6 and then I don't get what steps came in between