writing equations of parallel and perpendicular lines

Question

Write the equation of the line passing through (-1,4) and is perpendicular to x+4y=8

Answer 1

Write the equation of the line passing through (-1,4) and is perpendicular to x+4y=8

The line is y=-x/4+2. Any line perpendicular to it is of slope = 4

We want the equation of the line of that slope through the point (-1,4)

y=4x+b, 4=-4+b b=8

y=4x+8