Answer:
You have the slope of the line which is equal to
(8-3) ÷ (6-9) = 5/-3
And if you know a line's slope and you know a dot in this line, then you have the linear function
y - y1 = m(x - x1)
y - 8 = 5/-3(x - 6)
y = 5/-3x + 10 + 8
So y = 5/-3x + 18
