Perpendicular y intercept

Question

I need to find an equation for the line perpendicular to the line -2x+4y=-8 having the same y intercept as 4x-2y=-2

Answer 1

Perpendicular lines have negative reciprocal slopes.  First, we need put the line it is perpendicular to in   y=mx+b  form.

 

-2x + 4y = -8    ----->   4y = 2x - 8    ------>    y = (1/2)x - 2

 

 

The slope of the perpendicular line is -2.   This means that the equation of the line is

 

y = -2x + b

 

 

 

This perpendicular line has the same y-intercept as       4x - 2y = -2  .  Setting x=0 and solve for y from this given equation, the value of y=1.  So the equation that you want is

 

 

y = -2x + 1