Day 4

S represents the solution (#1)

• Objective: Students will create and solve a system of inequalities by graphing. 
• Similar to unit 5 day 4, when you graph an inequality you need to shade in the region according to the signs:    (<, >, <, >)  However, once you solve the two inequalities, you only shade in the region where the two lines have the same shaded area.  In other words, you don't shade in an area unless both lines' equations support it. 
• Watch this video for how to use this concept of linear inequalities in real life: http://www.sophia.org/linear-inequalities-in-the-real-world/linear-inequalities-in-the-real-world--3-tutorial

#2

Quiz!
1.) For the picture on the top right, where do you start making profit, or where is the profit margin?
2.)For the picture on the left, where is the profit margin and when do you start making profit?
3.) For the picture below #2, (bottom left) what is the profit margin?

Answers to quiz:
1.) You would start making profit where the red line crosses the 2 on the y axis and where the blue line crosses the 2 on the x axis.

2.) You would start making profit where the solid red line crosses the 5  on the x axis and where the dotted red line crosses the 5 on the y axis. (anything above their intersection which is (2,2) The profit margin is the blue shaded region.

3.) The profit margin is the percentage of selling price that is turned into profit, or in other words the purple shaded region on the graph.