1. Chapter 4 Unit Question How do we graph in algebra?

2. Open Learning Logs Date on Left…Section 4 – 7 on right

3. Section 7 Warm-Up What can you tell me about these graphs? (besides their color ) A C D B

4. Section 7 How do we compare linear situations graphically?

5. Homework Clicky

6. Graph on the same coordinate plane… y = 4x – 2 y = -3x + 1 6 2 -2 2 1 0 YX -5 -2 1 2 1 0 YX

7. Graph on the same coordinate plane… y = 3 x = -1 3 3 3 2 1 0 YX 2 1 0 YX

8. When we graph 2 lines on the same coordinate plane, we are looking for where they cross – the INTERSECTION – of the two lines This is the 1 st example. Where do the lines cross? Right here Which looks like point ( ____, ____ ) ½-¼

9. Adam ate 5 twinkies… then ate 2 an hour… Write an equation for Adam Mike ate 2 twinkies… then ate 3 an hour… Let x = hours and y = Twinkies eaten y = 5 + 2x Write an equation for Mike y = 2 + 3x Graph both When will they have eaten the same amount? Looks like when x = 3 Or 3 hours We can prove our answer algebraically…next slide please

10. Adam ate 5 twinkies… then ate 2 an hour… OR Adam’s = Mike’s Mike ate 2 twinkies… then ate 3 an hour… We said 3 hours their Twinkie eating will be EQUAL Yep, same answer --- 3 hours! Remember, we let x = hours

11. Car M travels at 25 MPH… is 30 miles ahead of Car N when Car N passes a checkpoint traveling at 30 MPH Write an expression for Car M Let x = hours 25x + 30 Write an expression for Car N 30x Graph both When will Car N catch up to Car M? Looks like when x = 6 Or 6 hours We can prove our answer algebraically…next slide please Hours Miles 1 2 3 4 5 6 7 8 9 200 180 160 140 120 100 80 60 40 20 0

12. Car M 25 MPH with 30 mile head start OR Car M = Car N Car N 30 MPH We said 6 hours cars will meet Yep, same answer --- 6 hours! Remember, we let x = hours

13. Homework Do HoffmaSheet 4 – 7