Topics for April 25th

Algebra I

Today we discussed
We finished our discussion about solving systems of equations and tackled some more complicated equations with rational numbers.  From there we graphed systems of inequalities to determine the solution - as with all inequalities, there are many possible solutions so the key is to find where the two graphs intersect.

Sections Covered in Textbook
1) 11-5: Elimination Using Multiplication (pages 457-461)
2) 11-5: Graphing Systems of Inequalities (pages 463-467)

Video Tutorials
1) How to Solve Systems of Equations by Graphing

• http://www.virtualnerd.com/algebra-1/systems-equations-inequalities/inequalities/solving-systems-inequalities/inequality-solve-by-graphing
• https://www.khanacademy.org/math/algebra/two-variable-linear-inequalities/graphing-inequalities/v/graphing-systems-of-inequalities-2

Assignments
1) Page 460 #'s 22, 24, 31
2) Page 465 #'s 13-33 2nd Column only


**PLEASE CHECK ODD ANSWER IN BACK OF TEXTBOOK

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Pre-Algebra

Today we discussed
We have finished our unit on graphing and now have moved into ratios, proportions and percents.  We defined a ratio as a comparison of two numbers by division.  Ratios can be expressed in three ways:

2 is to 3       or       2:3      or 2/3

A rate is defined as a ratio that compares two numbers with different measures like mile/hour.

Proportions can be formed by setting two ratios (fractions) equal to each other.  If we have a missing number, we can solve by multiplying the means and extremes and solving for the variable (missing value).

Sections Covered in Textbook
1) 9-1: Ratios and Rates (pages 324-325)
2) 9-2: Proportions (pages 327-329)

Video Tutorials
1) How to solve a proportion.
http://www.virtualnerd.com/pre-algebra/ratios-proportions/proportionality/solving-proportions/proportion-cross-multiply-example

Assignments
1) Look over chapter 8 to see if you have any questions (skip section on systems of equations)
2) Page 329 #'s 26-37 all

**PLEASE CHECK ODD ANSWER IN BACK OF TEXTBOOK

Algebra I

Today we discussed
Systems of Equations continues to be our topic of discussion and how to best solve them.  We've now covered three methods for solving systems, and have discussed the limitations of each method:

1. You may solve by graphing.  The limitation is we are prone to error and unless graphs are constructed very carefully, it is easy to make a mistake and not have line lines cross where they should.  There are tools available  to help with this method, including spreadsheets and graphing calculators  (Click here to try this online graphing calculator to check your work.)
2. You may solve by substitution.  Limitations for this method include equations that are in standard form must first be manipulated to solve for a variable, requiring an extra step, and equations with fractions require more cumbersome arithmetic.  
3. You may solve by elimination.  The goal of this method is to eliminate one of our variables so we and use it to find the second variable.  Most people agree that elimination is the preferred method because it works for every type of system.  

Sections Covered in Textbook
1)  11-4: Elimination Using Addition and Subtraction (pages 452-453)

Video Tutorials
1) Solving systems of equations using elimination method.
http://www.virtualnerd.com/algebra-1/systems-equations-inequalities/elimination/elimination-by-addition-subtraction/equations-solution-by-elimination-addition

Assignments
1)  Make any needed corrections to your graphing test on a separate sheet of paper.
2)  Page 455 #'s 13-31 odd, 37

**PLEASE CHECK ODD ANSWER IN BACK OF TEXTBOOK

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Pre-Algebra

Today we discussed
Our discussion graphing moved on to graphing inequalities.  We reviewed the difference between strictly less than or greater than (< , >) and less than or equal to or greater than or equal to (≤, ≥), and whether to include the line or not in the graph of the solution.  You can find another lesson on graphing inequalities by going here:

http://www.mathsisfun.com/algebra/graphing-linear-inequalities.html

Three Methods for Graphing Lines

How to Graph Inequalities

Sections Covered in Textbook
1) 8-11: Graphing Inequalities (pages 315-317)

Video Tutorials
1) Graphing Inequalities

• http://www.virtualnerd.com/algebra-1/linear-inequalities/two-variables-graphing/graphing-coordinate-plane/coordinate-plane-graphing-example
• https://www.khanacademy.org/math/algebra/two-variable-linear-inequalities/graphing-inequalities/v/graphing-linear-inequalities-in-two-variables-example-2

Assignments
1) Page 317 #'s 9-19 odd, 25

**PLEASE CHECK ODD ANSWER IN BACK OF TEXTBOOK