graph this

IDK

y = (1/2)x-4

First let x be some convenient  value, say, 0

So we have

y = (1/2) * 0   - 4  

y =  0 - 4

y = -4      ....sp....we have the point (0, -4)  on the graph

Next, let x be any other value.....I'll use 2

y = (1/2) * 2   - 4

y = 1 - 4

y = -3  .......so.......we have a second point, (2, -3).....plot this

Now.......draw a line though the two points.....voila !!!.....there's your graph !!!