The point-slope form:
[tex]y-y_1=m(x-x_1)[/tex]
We have the slope m = 4 and the point (1, 2). Substitute:
[tex]\boxed{y-2=4(x-1)}[/tex] use distributive property
[tex]y-2=4x-4[/tex] add 2 to both sides
[tex]\boxed{y=4x-2}[/tex] - slope-intercept form