1. Standard Form

2. Slope-intercept form  y = mx + b
Different Forms
Slope-intercept form  y = mx + b
slope
y-intercept
Standard form  Ax + By = C
Cannot both be 0
Point-Slope form  y – y1 = m(x – x1)
y-coordinate
slope
x-coordinate

3. Finding the x-intercept and y-intercept
Standard form  2x + 4y = 12
To find the x-intercept, substitute 0 for y and solve for x.
To find the y-intercept, substitute 0 for x and solve for y.
2x + 4(0) = 12
2(0) + 4y = 12
2x = 12
x = 6
4y = 12
y = 3
x-intercept is (6,0)
y-intercept is (0,3)

4. Finding the x-intercept and y-intercept
4x – 9y = 18
5x + 2y = -10
4x – 9(0) = 18
5x + 2(0) = -10
4x = 18
x = 4.5
5x = -10
x = -2
x-intercept is (4.5,0)
x-intercept is (-2,0)
5(0) + 2y = -10
4(0) – 9y = 18
-9y = 18
y = -2
2y = -10
y = -5
y-intercept is (0,-2)
y-intercept is (0,-5)

5. Graphing Lines Using Intercepts
2x + 3y = 12
Steps
1) Find the intercepts 
2x = 12
x = 6
(6,0)
3y = 12
y = 4
(0,4) 
2) Plot the intercepts
and draw a line
through the points.

6. Graphing Lines Using Intercepts
5x + 2y = -10 1)
5x = -10
x = -2
(-2,0)
2y = -10
y = -5
(0,-5) 2)   
4x – 9y = 18
4x = 18
x = 4.5
(4.5,0)
-9y = 18
y = -2
(0,-2) 

7. Graphing Horizontal and Vertical Lines
y = -3
Steps
1) Write in standard form if needed
0x + 1y = -3
2) This means that for all values of x, y = -3  
x = 2
1) 1x + 0y = 2
2) This means that for all values of y, x = 2

8. Graphing Horizontal and Vertical Lines
y = 5
y = -1 
x = -4   
x = 6

9. ¿Preguntas?
est-ce que vous en avez?

10. Assignments
Class Work
Page 333 #1 – 18
#19 – 25 odd
Page 334 #38 – 46
Homework
Page 335 #73 – 76