This is currently your equation since you do not know "b"
y = 2/3x + b
To find "b" you plug in the point (4,2) into the equation.
y = 2/3x + b
2 = 2/3(4) + b
2 = 8/3 + b (subtract 8/3 on both sides to get "b" by itself)
2 - 8/3 = b (make the denominators the same)
6/3 - 8/3 = b
-2/3 = b
So: y= 2/3x - 2/3
