Warm up Solve the given system by substitution

Warm up Solve the given system by substitution: 1) 2 x – y = 7 3 x + 3 y = - 3 Solve the given system by elimination: 2) -3 x + 4 y = -4 3 x – 6 y = 6

Questions over hw?

Summary of Methods 1) Substitution: Requires that one of the variables be isolated on one side of the equation. It is especially convenient when one of the variables has a coefficient of 1 or -1. 2) Elimination: Can be applied to any system, but it is especially convenient when a variable appears in different equations with coefficients that are opposites. 3) Graphing: Can provide a useful method for estimating a solution.

Summary of Solving Systems by Westerville South H. S. “All I do is Solve” http: //www. schooltube. com/ channel/westervillesouthmat h/

Best Method Graphing, Substitution, Elimination? 1. y = 4 x – 3 5 x – 2 y = 6 2. 4 x – 5 y = 13 2 x + 5 y = 5

Best Method 5. 3 x – 2 y = 6 y = 2 x – 4 6. x + y = 4 2 x + 3 y = 7

Skills Check Clear off your desk. Pencil and calculator only. Show all of your work. Circle your answer (check your answer if time permits). When you are finished sit quietly.

Solving Word Problems Using Systems

Steps Define all variables. 2. Write the system of equations. 3. Solve using best method & showing all steps. 4. State your solution in sentence form. 5. Check your solution. 1.

1. You are selling tickets for a high school basketball game. Student tickets cost $3 and general admission tickets cost $5. You sell 350 tickets and collect $1450. How many of each type of ticket did you sell?

Define variables: Solve S = # of Student Tickets G = # of General Admin Tickets System of equations: S + G = 350 3 S + 5 G = 1450 G = 200 State your solution(s): I sold 200 general admission tickets and 150 student tickets. S = 150

2. Last Saturday Missy bought pants and shirts. Each shirt cost $125 and each pair of pants cost $225. She came home with 26 items and spent exactly $4950. How many pants and shirts did Missy buy?

Define variables: Solve S = # of Shirts P = # of Pants System of equations: S + P = 26 125 S + 225 G = 4950 P = 17 State your solution(s): Missy bought 17 pairs of pants and 9 shirts. S = 9

3. You are in charge of decorating the gym for the Homecoming dance. You purchased 6 bags of balloons and 5 bags of large sparkling hanging stars all for $19. 20. You soon realized that this was not enough to decorate the entire gym. On your second trip to the store, you bought 8 bags of balloons and 2 bags of large sparkling hanging stars all for $15. 80. What was the price for each item?

Define variables: Solve B = price of a bag of balloons S = price of a bag of stars System of equations: 6 B + 5 S = 19. 20 8 B + 2 S = 15. 80 State your solution(s): The price of the bag of balloons is $1. 45 and the bag of stars is $2. 10. B = 1. 45 S = 2. 10

4. Wally World had a sale on DVDs and CDs for Labor Day weekend. Katie bought 3 DVDs and 2 CDs and spent $42. Emily bought 5 DVDs and 1 CD and spent $56. How much does each DVD and CD cost?

Define variables: Solve D = cost of DVD C = cost of CD System of equations: 3 D + 2 C = 42 5 D + C = 56 D = 10 State your solution(s): A DVD cost $10 and a CD costs $6. C = 6

Homework Worksheet Quiz tomorrow!