9.2 Representing Linear Functions

Graphing Equations

• Make a Table

Making a Table

1. Solve the equation for y

2. Pick your x values (-1, 0,1, 2)

3. Plug in the x values into x in the equation to find the corresponding y values

4. Plot the (x, y) ordered pairs on the coordinate plane

Solve for ‘y’9 20x y

Solve for ‘y’ means “get y all by itself”

9x 9x9 20x y

8

6

4

2

-2

-4

-6

-8

-10 -5 5 10 x

yFind 4 solutions

y = 2x + 1 X Values Y=2x + 1 Y Values

(x,y)

1

0

-1

2(1) +1 3 (1,3)

2(0) +1 1 (0,1)

2(-1) +1 -1 (-1,-1)

2 2(2) +1 5 (2,5)

8

6

4

2

-2

-4

-6

-8

-10 -5 5 10 x

Graph: Y=-3x

x Y=-3x y (x,y)

21

0

-1

-3(2)-3(1)

-3(0)

-3(-1)

-6-3

0

3

(2,-6)(1,-3)

(0,0)

(-1,3)

8

6

4

2

-2

-4

-6

-8

-10 -5 5 10 x

yGraph:

-2x + y = 5y = 2x + 5

x Y=2x+5 y (x,y)

1

0-1

2(1) +5 7 (1,7)

2(0) +5 5 (0,5)

2(-1)+5 3 (-1,3)

2 2(2) +5 9 (2,9)

•Assignment:

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