Parallel lines have the same slope. With this in mind, consider the given equation.
y= -4x+1
We see that the slope of the above line is -4. Therefore, the slope of any parallel line will have a slope of - 4. Using this information, we can write a general equation in slope-intercept form for any line which is parallel to the given one.
y= -4x+b
We are asked to write the equation of a parallel line to the given one that passes through the point ( 3, - 1). By substituting 3 and -1 for x and y, respectively, in the above formula, we will be able to find the y-intercept b.