Explanation:
Although I can't give you a written answer, here's how you do it.
For y = -x + 7, we know 7 is our y coordinate, so place a point on 7 on the y axis.
-x is equal to -1/1, so when graphing the line, go down 1 over 1 and place your point. Continue until you reach the edge of the graph.
For 5x + 5y = 10, subtract 5x from the left side of the equation. This will leave you with:
5y = -5x + 10. Divide every term by 5, leaving you with y = -x + 2. Your teacher may want you to phrase this as y = 2 - x. 2 is your y coordinate, and once again -x is -1/1. Start at 2 and go down 1 over 1 on the graph.