Answer:
13. 1/4x
14. -2/4x or -1/2x
15 1/3x or 2/6x
16. Zero
Step-by-step explanation:
13. goes up once and goes to the side 4 times
14. goes down twice and goes to the side 4 times
15. goes up one time and three to the side
16. zero slope, the line is horizontal
