1. Math 015 Section 6.6 Graphing Lines

2. Objective: To check solutions of an equation in two variables. Question: Is (-3, 7) a solution of y = -2x + 1 ? y = -2x + 1 Replace x with -3 Replace y with 7 7 = -2(-3) + 1 7 = 6 + 1 7 = 7 Both sides of the equation simplify to the same thing. Yes, (-3, 7) is a solution

3. Question: Is (3, 2) a solution of y = x + 5 ? y = x + 5 Replace x with 3 Replace y with 2 2 = 3 + 5 2 = 8 Both sides of the equation are not the same. No, (3, -2) is not a solution Objective: To check solutions of an equation in two variables.

4. Problem: Find the ordered pair solution of y = -3x + 1 that corresponds to x = 4 y = -3x + 1 If x = 4, then y = -3(4) + 1 so y = -11 Solution: (4, -11) Find the ordered pair solution that corresponds to x = 0 y = -3x + 1 If x = 0, then y = -3(0) + 1 so y = 1 Solution: (0, 1)

5. Problem: Graph the ordered-pair solutions of y = 2x – 1 when x = -2, 0, 1 and 3 y = 2x - 1 y -2-5 0 11 35 3 3 x

6. Graph: y = x xy -3 0 3 -2 0 2 y = x 2323 2323

7. Graph y = -3x + 2 2 xy -2 0 2 5 2 y = -3x + 2 2

8. Graph: y = 3x – 5 xy 0 1 -8 -5 -2 y = 3x – 5

9. Answer the following questions for the graph shown below. What is the y-value when x = -3 ? 2 What is the y-value when x = 5 ? -8 What is the x-value when y = -2? 1