Day 2: Solving Linear Systems by Graphing Unit 2: Linear Systems Did you know that unless food is mixed with saliva, you can’t taste it?

Learning Goals To be able to find a solution to two linear relations by graphing

Graph each of the following lines using an appropriate method (table of values, intercepts, slope/y-intercept) 𝑦=−𝑥+4 𝑥−2𝑦=10

𝑦=−𝑥+4 𝑚=−1 𝑦−intercept=(0, 4) 𝑥−2𝑦=10 0 −2𝑦=10 − 2𝑦 2 = 10 −2 𝑦=−5 𝑥−2 0 =10 𝑥=10

What are the coordinates of the point of intersection of these two lines? (6, −2) This ordered pair is called the solution to the linear system: it is the point that satisfies both equations. It is also called the point of intersection (POI).

Stephanie wants to rent a car for a weekend trip Stephanie wants to rent a car for a weekend trip. Kelly’s Kars charges $95 for the weekend plus $0.15/km. Rick’s Rentals charges $50 for the weekend plus $0.26/km. Which company charges less? Step 1: Write ‘Let…” statements Let 𝑥 represent the distance driven in km Let 𝑦 represent the total cost of the car rental in dollars

Stephanie wants to rent a car for a weekend trip Stephanie wants to rent a car for a weekend trip. Kelly’s Kars charges $95 for the weekend plus $0.15/km. Rick’s Rentals charges $50 for the weekend plus $0.26/km. Which company charges less? Step 2: Write an equation for each option 𝑦=0.15𝑥+95 Kelly’s Kars 𝑦=0.26𝑥+50 Rick’s Rentals

Stephanie wants to rent a car for a weekend trip Stephanie wants to rent a car for a weekend trip. Kelly’s Kars charges $95 for the weekend plus $0.15/km. Rick’s Rentals charges $50 for the weekend plus $0.26/km. Which company charges less? Step 3: Decide the easiest method to graph (table of values, intercepts, slope/y-intercept) Since both are in 𝑦=𝑚𝑥+𝑏 form, slope/y-intercept is easiest

Stephanie wants to rent a car for a weekend trip Stephanie wants to rent a car for a weekend trip. Kelly’s Kars charges $95 for the weekend plus $0.15/km. Rick’s Rentals charges $50 for the weekend plus $0.26/km. Which company charges less? Step 4: Graph each line

Stephanie wants to rent a car for a weekend trip Stephanie wants to rent a car for a weekend trip. Kelly’s Kars charges $95 for the weekend plus $0.15/km. Rick’s Rentals charges $50 for the weekend plus $0.26/km. Which company charges less? Step 5: Find the point of intersection (409, 156)

Stephanie wants to rent a car for a weekend trip Stephanie wants to rent a car for a weekend trip. Kelly’s Kars charges $95 for the weekend plus $0.15/km. Rick’s Rentals charges $50 for the weekend plus $0.26/km. Which company charges less? Step 6: Give a concluding statement If Stephanie drives 409 km, both companies charge the same. If she drives less than 409 km, Rick’s Rentals charges less. If she drives more than 409 km, Kelly’s Kars charges less.

Graphing Calculators www.meta-calculator.com Desmos app

Find the solution (or the POI) to the following two equations using graphing technology. 4𝑥+3𝑦=6 𝑦= 1 4 𝑥−3

Success Criteria I CAN find the solution (or the point of intersection) for two linear equations by graphing by hand or using technology

To Do… pg. 26 # 1, 2a, 3, 4, 5c, 6, 8, 9, 14a Screenshot 3c) and post to Twitter @MrsMcCrumBHS #coolgraph Extra help Tuesday after school, Thursday at lunch (rm 209) Check the website daily for updates, missed notes, assignment solutions www.mrsmccrum.weebly.com