What is slope intercept form?

In slope intercept form, $$y=mx+b$$  

which variable is the slope?

Which line would be parallel to $$y=-\frac{1}{2}x+4$$  

Which line would be perpendicular to $$y=-\frac{1}{2}x+4$$  

Are these 2 lines parallel, perpendicular or neither?

$$y=4x-4$$  

$$y=-4x+2$$  

Are these 2 lines parallel, perpendicular or neither?

$$y=-\frac{2}{3}x+7$$  

$$y=\frac{3}{2}x-7$$  

Are these 2 lines parallel, perpendicular or neither?

$$y=5x-4$$  

$$y=5x+7$$