Algebra 2: Lines and Systems

I'm trying to cram in a unit on systems of equations and inequalities before break. It's hard, since so many students are still not totally comfortable with graphing linear functions. But we're making progress. We're up to solving 3x3 systems with linear combination, and most of them have got the idea. These problems are huge, and are probably the longest routine problems my students have ever done. This is cool, because it makes them feel smart and accomplished when they get one right. Unfortunately, a single arithmetic or copying error (which happen all the time) can crumble the whole thing, and then the frustration is back again, eating away at their self-confidence. I'd like to get to graphing systems of linear inequalities before break. When we get back, we need to review for the final, but I'd really like to do some work with linear programming problems first. Here are the files from the last few lessons.

Lesson 1 (Linear Functions) / Keynote / Quicktime
Lesson 2 (2x2 Linear Combination) / Keynote / Quicktime
Lesson 3 (2x2 Word Problems) / Keynote / Quicktime
Lesson 4 (3x3 Systems)
Lesson 5 (Systems Practice)