Answer:
1. Undefined
2. Negative
3. Zero
4. Positive
Step-by-step explanation:
1. Undefined, the line moves in both directions vertically. It's impossible to tell what the slope is.
2. Negative, the line is decreasing at a constant rate, the slope is negative.
3. Zero, the line doesn't increase or decrease, therefore the slope is 0. (No changes)
4. Positive, the line is increasing at a large rate, the slope is positive.
