Answer:
--- Slope intercept
--- Point slope
Step-by-step explanation:
Given
Perpendicular to 
Required
Determine its equation
The general form of an equation is:

Where

By comparison:

Next, we calculate the slope of L.
Because L is perpendicular to
, the relationship between their slopes is:

Substitute 4 for m

The equation of L in slope intercept form is: 
Substitute -1/4 for m

In point slope form, we have:

Substitute -1/4 for m
