1. -3 1 2 3 4 5 -1 -2 -4 -5 -6
Y-axis A
Quadrant 2
Quadrant I
(4,2)
2 up
4 right 1 2 3 4 5 6 -1 -2 -3 -4 -5 -6
X-axis B C
Quadrant 4
Quadrant 3
Each point is called an ordered pair. ( x, y)

2. -3 1 2 3 4 5 -1 -2 -4 -5 -6 1 2 3 4 5 6 -1 -2 -3 -4 -5 -6
Plot each ordered pair
A= ( 2, -6)
C = ( -5, 0)
B = (0, 4)
D = ( - 4, - 5)
E = ( 4, 3/2)

3. -3 1 2 3 4 5 -1 -2 -4 -5 -6
All points on the x axis have y values equal to 0 1 2 3 4 5 6 -1 -2 -3 -4 -5 -6
All points on the y axis have x values equal to 0.

4. -3 1 2 3 4 5 -1 -2 -4 -5 -6
All points have y = 3 1 2 3 4 5 6 -1 -2 -3 -4 -5 -6
All points have y = -4
Conclusion: All points on Horizontal lines have the same y value!!!!

5. -3 1 2 3 4 5 -1 -2 -4 -5 -6
All points have x = -4 1 2 3 4 5 6 -1 -2 -3 -4 -5 -6
All points have x = 2
Conclusion: All points on a vertical line have the same x value!!!!

6. 1) What is the balance in the account after 3 months?
$6000
2) What is the balance in the account after 8 months?
$3000

7. Equations in Two Variables
2x + 3y = -4
y = x² + 9
y = x³ - 1

8. To solve an equation with one variable, such as x + 3 = 7 means to find the value for x that makes the equation true. The solution is x = 4.
Question :What does it mean to solve an equation, like - 2x + y = 1 that has two variables?
Answer: To find all ordered pairs from the cartesian coordinate system that makes the equation true.

9. Let’s look at -2x + y = 1 Is ( 0, 2) a solution? -2(0) + ( 2) = 1
0 + 2 = 1 False
Try ( 2, 5)
-2(2) + ( 5) = 1
= 1 True
Try ( -1, -1 )
-2( -1) + ( -1) = 1
2 + (-1) = 1 True

10. How do you find solutions to an Equation in Two Variables?
You simply plug in x values and solve the equation for y.
Let’s return to the equation -2x + y = 1
If I plug in x = 3, then I can find the corresponding y value
-2( 3) + y = 1
So ( 3, 7) is a solution to the equation.
- 6 + y = 1
y = 7

11. x y (x,y) Find more solutions for - 2x + y = 1 by filling in the chart-2 -3
(-2,-3) 1 3
(1,3) 5 2
(2,5) 1
(0, 1) -1 -1
(-1,-1)

12. -3 1 2 3 4 5 -1 -2 -4 -5 -6 1 2 3 4 5 6 -1 -2 -3 -4 -5 -6
All the points on this line represent solutions to the equation -2x + y = 1