Explanation:
x - 4y = 12
x - 12 = 4y
y = (1/4)x - 3
the slope of this line is the factor of x : 1/4
the parallel line has the same slope, of course.
so, its line function is
y = (1/4)x + c
c is the y-intercept. and we get it by using the provided point coordinates :
-4 = (1/4)×8 + c
-4 = 2 + c
c = -6
so, the equation of the parallel line is
y = (1/4)x - 6