Use a graphing utility to graph each set of equation on the same screen; then sketch what you see on a sheet of graph paper. Look for a relationship between the equations. Clear the screen between each set.

1. a. y = x; y = x + 1; y = x + 3; y = x - 4.

d. y = -x + 4; y = -x + 1; y = -x; y = -x - 5.

2. Describe the relationship among the lines in each set. What conclusions

can you draw?