There is the picture Help please

almost! for the ones you're missing:

for y=1/2x-3 slope is 1/2, y intercept is -3, x intercept 1/2, and it is linear.

for y=-2x the slope is 2, y intercept would be zero

for the ones who don't have any y intercept defined, it would automatically be zero by the way your teacher might take points off for that