1) It is a horizontal line through (0, 2) with no x-intercept. The slope is zero.
2) It is a decreasing line that only goes through the origin on the axis. The slope is -1/2.
3) It is an increasing line that crosses the y-axis at 4 and the x-axis at 4. The slops is 1.
4) is is a vertical line going through (-1, 0). The slope is undefined.