Do you want the equation of a line through that point (1,2) with slope m = 4?
Use the equation
(y-y*) = m(x - x*)
where x* and y* are the coordinates of the point the line has to pass through.
(1,2)m=4
Use the equation
(y-y*) = m(x - x*)
where x* and y* are the coordinates of the point the line has to pass through.
(1,2)m=4