1. 0123456-2-3-4 -5 -6 -3 1 2 3 4 5 -2 -4 -5 -6 X-axis Y-axis Each point is called an ordered pair. ( x, y) (4,2) A B C Quadrant IQuadrant 2 Quadrant 3 Quadrant 4 4 right 2 up

2. 0123456-2-3-4 -5 -6 -3 1 2 3 4 5 -2 -4 -5 -6 Plot each ordered pair A= ( 2, -6) B = (0, 4) C = ( -5, 0) D = ( - 4, - 5) E = ( 4, 3/2)

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

4. Linear Equations in Two Variables Ax + By = C A, B, C are real numbers 2x + 3y = -4 -x + y = 9

5. To solve an equation with one variable, such as x + 3 = 7 meant 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 + 3y = 6 that has two variables? Answer: To find all ordered pairs from the cartesian coordinate system that makes the equation true.

6. Let’s look at -2x + y = 1 Is ( 0, 2) a solution?-2(0) + ( 2) = 10 + 2 = 1 False Try ( 2, 5)-2(2) + ( 5) = 1-4 + 5 = 1 True Try ( -1, -1 ) - 2( -1) + ( -1) = 12 + (-1) = 1 True

7. How do you find solutions to an Equation in Two Variables? You simply plug in x values and solve the equation for x. 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 - 6 + y = 1 y = 7 So ( 3, 7) is a solution to the equation.

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

9. 0123456-2-3-4 -5 -6 -3 1 2 3 4 5 -2 -4 -5 -6 All the points on this line represent solutions to the equation -2x + y = 1