Consider the line 4x + 8y = -4. a) What is the slope of a line perpendicular to this line?

b) What is the slope of a line parallel to this line?

A) -2

a slope of a line perpendicular is it’s opposite and reciprocal.

Therefore you want to find the slope. You can do this by writing it in intercept form, or just knowing A/B since it’s in standard form.

slope form: y= mx + b

8y = -4 -4x

y = -1/2x -1/2

So the slope is -1/2 so it’s opposite and reciprocal would be 2. So a slope of a line perpendicular is -2.

b) -1/2

A line parallel would have the same slope as your equation. Since you know the slope -1/2 you know whatever your b value is, that line would be parallel as long as it has the same slope.

What can we do about it

The scale factor of what ?