1. October 27, 2011 Ms. Wu says … get to work! 1.Copy homework into planner. 2.Get your HW 2.4 out. 3.Work on the warm up quietly in pen. ________________________________________________ 33) a = -4 41) j = 10 4)y = -5/2x + 23 6) y = 5x + 7 7) y = 6x + 1 12)parallel: none perpendicular: a and b 23) y = -3/4x – 4 25)y = -1/2x – ½ 29)Yes, because -1/4 is the negative reciprocal of 4 34)Park and 2 nd are parallel (slopes are both 2/3) Sea and Park, Sea and 2 nd are perpendicular (Sea’s slope is - 3/2)

2. Ex 3: Write an equation of the line that passes through (-1, 3) and is parallel to y = 2x + 2

3. Ex 4: Write an equation of the line that passes through (-9, 2) and is perpendicular to y = 3x – 12

4. The Correlation between Ms. Wu’s Sleep Schedule and Ms. Wu’s Work Habits

5. Intercepts or “zeroes” X –intercept: y – intercept:

6. The Standard Form Definition: If A, B, and C are integers where A and B are both not zero, then Ax + By = C is called the Standard Form of a linear equation. All linear equations can be written in Standard form, whether or not they are functions.

7. Before we talk more about standard form, how do we find the intercepts of 2x +y = 4? To find the x- intercept, set ______ = 0. To find the y – intercept, set _____ = 0.

8. The Standard Form—What are the values of A, B, and C? Examples: 3x + 5y = 7 -2x + 6y = 17 x – 4y = 15 18x – 8y = -16

9. Standard Form Ax + By = C Horizontal Lines:Vertical Lines: When A = 0When B = 0 Ex: 3y = 18Ex: 4x = 24

10. The Standard Form In Standard Form: -4x + 5y = 6 -3x – y = -2 x = 3 2y = -16 Not Standard Form: - ½ x +5y = 6 y = 2x - 4 y = 2x + 3y x = 2(y- 4)

11. Transform 4x + 2y = 8 and 12x + 6y = 24 into slope – intercept form.

12. Simplified Standard Form A standard form equation is considered “simplified” when the following conditions are met: 1)A is non-negative 2)A, B, and C are relatively prime (don’t share any factors except 1) SimplifiedNot Simplified 2x + 3y = 73x – 6y = 12 -2x + y = -2

13. Simplifying Standard Form When A is negative… Multiply all of the terms by –1 Ex: -3x + 2y = 7 When A, B, and C have a common factor Divide all terms by that factor Ex: 3x + 6y = -12

14. Simplify -2x + 6y = 8.

15. Graphing in Standard Form Steps to graphing from Standard Form: a) Find the x-intercept (plug 0 in for ______ and solve) b) Find the y-intercept (plug 0 in for ______ and solve) c) Plot the intercepts d) Connect the intercepts with a straight line

16. Graphing in Standard Form Graph: 2x + y = 3