Chapter 4 Unit Question How do we graph in algebra?

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

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

Section 7 How do we compare linear situations graphically?

Homework Clicky

Graph on the same coordinate plane… y = 4x – 2 y = -3x YX YX

Graph on the same coordinate plane… y = 3 x = YX YX

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

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

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 hours! Remember, we let x = hours

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

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 hours! Remember, we let x = hours

Homework Do HoffmaSheet 4 – 7