Graphing Linear Equations

Do the points fall on the graph of the line

4x + 2y = 18a. (1,8) 4 + 16 =

18

a. 4(1) + 2(8) = 18

b. (3,3) 20 = 18

b. 4(3) + 2(3) = 18

12 + 6 = 18 18 = 18

15x + 5y = 5

a. (-2,7)

No Yes

b. (-1,4)

a. 15(-2) + 5(7) = 5

b. 15(-1) + 5(4) = 5

-30 + 35 = 5

-15 + 20 = 55 = 5 5 = 5

Yes Yes

Find three different ordered pairs that are solutions

y = 2x + 10

x y = 2x + 10 y

1 y = 2(1) + 10 12

0 y = 2(0) + 10 10

-1 y = 2(-1) + 10

8

(1,12)(0,10)(-1,8)

y = -x + 5

x y = -x + 5 y

1 y = -1(1) + 5 4

0 y = -1(0) + 5 5

-1 y = -1(-1) + 5 6

(1,4)(0,5)(-1,6)

Rewrite the equation in function form

4x + 2y = 20-4x -4x

2y = -4x +20 2 2

y = -2x +10

5x + y = -5

-5x -5x

y = -5x - 5

Use a table of values to graph the equation

y = 4x - 1

x y = 4x - 1 y

-1 y = 4(-1) - 1

-5

0 y = 4(0) - 1

-1

1 y = 4(1) - 1

3

y = -3x + 1

x y = -3x + 1 y

-1 y = -3(-1) + 1

4

0 y = -3(0) + 1

1

1 y = -3(1) + 1

-2