January 9Ms. Wu says … follow the instructions below!

1) Find your new seat.2) Get out HW 3.2 (don’t have to tear out).3) Get started on the warm up quietly.4) Grade HW 3.2._______________________________________________4. (-3, 29)7. (5, 7)10.(-2, 2)13.(4, 5)16.(-15, -62)20.(5, 3)23. The two equations should be subtracted rather than

added; 6x – 8; x = 4/3

27.(-4, 12)32.(10, 6)34. a. 2 = m + b; 12 = -4m + b b. m = -2, b = 4

c. y = -2x + 435. L = 4.5 ft; w = 2.5 ft.

New stuff for 2nd semester:• Warm ups

– Will not be turned in; grade in class; 10% final grade; points deducted for talking/not doing it/being off-task

• Quicky quizzes– Every class period; worth 5 – 10 pts; drop 2 lowest scores; if

absent, counts as dropped score • Late homework

– Name on door for a week; if not crossed off, mandatory tutorials (call home)

• Homework quizzes– Worth 10 pts.; can use homework; cannot drop or make up; if

absent, grade homework as quiz

The Elimination Method, pt. 2

Ex1: 3x – 4y = 14 2x + 2y = 21

The Elimination Method, pt. 2

Ex 2: 5x – 6y = 12 3x – 5y = 24

The Elimination MethodProcess:

1) Pick the variable you want to eliminate.2) Multiply one, or both, equations by a value to

make sure the coefficients of the chosen variable are the same (for subtraction) or opposite (for addition).

3) Subtract/Add and Solve the resulting equation.4) Go back to one of the original equations and

solve for the other variable.

Group Activity• Study the following Linear Inequalities and

determine at least 5 different points (x, y) that make each inequality true.

• Plot the points on the board. You cannot plot the same point as another group!

• What do you notice about the points that make each linear inequality true?

A) x ≤ 4 B) y > -2

C) y < ½ x – 2 D) 2x – y ≥ 4

Graphs from the activity.A

B

CD

Steps to Graphing

1) Graph the boundary line2) Determine if the boundary is inclusive (solid

line) or exclusive (dotted/dashed line)3) Test a point and shade the appropriate half

plane.

Graphing Linear Inequalities

The graphs consist of 1) Boundary Line (graph of corresponding equation)

---- for exclusive___ for inclusive

2) Half-Plane (shaded to indicate included points)

Half-Plane: The points on a plane that fall on one side of a boundary line.

Sample Problems1) Determine if (4, 5) is a point that satisfies

4x + 2y < 122) Write inequalities that describes the

graphs below.

SIGMA #3• 10 pt class work grade• 30 minutes, calculators allowedSIGMA Score Classwork Grade

8 13

7 12

6 11

5 10

4 9

3 8

2 7

1 6

0 5

Quicky Quiz

• 5 minutes• Worth 5 points• No notes allowed

HW 3.3

• Pgs 454 – 455: 5, 7, 11, 13, 21, 23, 27, 31, 33, 37