Answer:
 A. y = 2x -9
 B. y = -1/2x +1
Explanation:
The given line is in slope-intercept form
 y = mx + b
where m is the slope. For your given line, the slope is 2.
A. A parallel line will have the same slope. It is convenient to start with a point-slope form of the equation for the line:
 y = m(x -h) +k . . . . . for slope m through point (h, k)
You want the equation of the line through (4, -1) with slope 2, so its equation is ...
 y = 2(x -4) -1
Simplifying to slope-intercept form, this becomes ...
 y = 2x -8 -1
 y = 2x -9
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B. A perpendicular line will have a slope that is the opposite of the reciprocal of the slope of the given line. That slope is ...
 m = -1/2
As above, the point-slope form of the perpendicular line is ...
 y = -1/2(x -4) -1
 y = -1/2x +1 . . . . . after simplification