PLEASE HELP. I NEED ALL!!!!

y=6x if x = 1

y=6x if x = 2

y=6x if x = 3

y=6x if x = 4

y=.5x if x = 1

y=.5x if x = 2

y=.5x if x = 3

y=.5x if x = 4

y=-0.2x if x = 0

y=-0.2x if x = 1

y=-0.2x if x = 2

y=-0.2x if x = 3