1. Warm Up
1) Write the equation of a line in slope intercept form that has a slope of -3 and a y-intercept of 2.
2) Write the equation of a vertical line through the point (-4, 7)
Find the slope and y-intercept of the following:

2. Standard Form of an Equation
Unit 4B Day 1
Standard Form
of an Equation

3. Standard Form of an Equation
Write the equation for STANDARD FORM: Ax + By = C A, B, and C must be whole numbers and A and B are both not zero

4. Change to Standard Form
Examples of Standard Form
3x + 5y = 3
-2x + y = 7
2x − y =6
Equations Non-Examples
x = 6 − y
y = 2x + 7
2y = 4x +2

5. When is Standard Form useful?
When you want to graph the line
When you want to know the y- intercept of the line
When you want to know the x- intercept

6. Examples Change each equation into Standard Form: 2y = 4x – 6
x + 7 = ½y
x = -3y - 8

7. Try on your own:
4. 9x + 4 = -y 5. y = -5x ¼x – ¾y = -1

8. Find the y-intercept
The y-intercept always occurs when x=___. To find the y-intercept of a line when the equation is in Ax + By = C, plug 0 into x in the equation and solve for the y value.

9. Find the y-intercept
2x – y = -6
-2x + 4y = 12

10. Find the x-intercept
The x-intercept always occurs when y=___. To find the x-intercept of a line when the equation is in Ax + By = C, plug 0 into y in the equation and solve for the x value.

11. Find the x-intercept
2x – y = -6
-2x + 4y = 12

12. Graphing from standard form
- Find both the x and y intercepts
- Plot the intercepts
- Connect to form the line

13. Find the x & y intercepts and Graph

14. Write the equation of the situation:

17. Class work WS

18. Classwork

19. Coming up…
HW 4.2B tonight
Tutoring today after school
Quiz Friday