Algebra I
Today we discussedSystems 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:
- 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.)
- 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.
- 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
Pre-Algebra
Today we discussedOur 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
