Wednesday, March 12, 2008
Algebra (Class 59)
Announcements
Test Friday focusing on work from Investigation 3 and Investigation 5. Rework the hard problems from the ACE and the warm-ups!
Lesson Title
Systems of Linear Inequalities
Overview
In today’s class our warm-up continues to focus on using tables and patterns to organize data and to help us find patterns we can use for writing equations. In the lesson for the day we continue our work with linear inequalities by learning how a system of two linear inequalities can be used to solve a problem.
Textbook Sections
§10-7 (Txt. p.490) Graphing Linear Inequalities
The Shapes of Algebra- Investigation 5.4 (p. 76)
Vocabulary
inequality
systems of linear inequalities
region
constraint
Key Attitudes
Math is about investigating and confirming
Key Ideas
Inequalities are used to represent situations where there is a limiting value.
Solutions to inequalities can be graphed on a number line when there is only one variable.
Solutions to inequalities are represented by a region on a two axis graph when two variables are involved.
When multiplying or dividing by a negative value, the direction of the inequality switches.
In equalities can include or not include the limiting value. We use a closed circle on the number line to represent including the limiting value and an open circle to represent not including the limiting value.
To find the solution to a system of two (or more) linear inequalities you need to find where the shaded regions overlap.
Key Skills
Find ordered pairs which satisfy two sets of constraints.
Graph a linear inequality on a coordinate plane.
Determine the region that satisfies a system of inequalities by trying points.
Match a linear inequality to its graph.
Solve a system of two linear inequalities by graphing.
Turn-In (#58)
ACE p.78 #2, 4, 5
ACE p.42 #40, 46
Handouts
Extra Practice 26- Inequalities in Two Variables
Assignment
ACE p.42 #41, 47
ACE p.78 #6, 7, 9, 11
Extra Practice 26 #1, 2, 7-12
Disclaimer- The assignment as stated in class is the official assignment. Every effort is made to keep this posting accurate, but you should refer to what was stated in class as the final word.
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