I can solve a system by substitution.

Transcription

1 Lesson: 7.2 day 2 Date: LT#3: I can solve a system by substitution. substitution = nbp.3 Steps to solve a system by substitution = step 1: step 2: step 3: Example:1 Solve the system. (substitution) y = 3x + 2 x + 2y = 11 Example:2 Solve the system. (substitution) x 2y = 6 4x + 6y = 4 Summary

2 Identify each variable (2 per question). 7.2 day 2 CW Write equations (2 per question). Solve each system using the substitution method. Your school is selling football tickets for a home game. The school sold 35 tickets for $86 on the first day of the sale. Student tickets cost $2 each and non student tickets cost $3 each. Find the number of student tickets and the number of not student tickets the school sold. s = n = (, ) nbp.3 You burned 8 calories per minute on a treadmill and 10 calories per minute on the elliptical trainer for a total of 560 calories in 60 minutes. How many minutes did you spend on each machine? t = e = (, )

3 Identify each variable (2 per question). 7.2 day 2 CW Write equations (2 per question). Solve each system using the substitution method. As the student council treasurer, you prepared the budget for your class rafting trip. Each large raft costs $100 to rent, and each small raft costs $40 to rent. If you rent 32 rafts and spent $2480, how many large and small rafts did you rent for the trip? l = s = (, ) Sam is going to the state fair. She has two ticket options as shown in the table. Write an equation that shows the cost per person for each option. Then use substitution to solve the system of equations. r = # of rides t = total cost (, )

4 IF Identify the variables Write a system It takes you 3 hours to mow a lawn and 2 hours to trim hedges. You spend 16 hours doing yard work and completed 6 jobs.

5 IF Identify the variables Write a system Your school is selling football tickets for a home game. The school sold 35 tickets for $86 on the first day of the sale. Student tickets cost $2 each and non student tickets cost $3 each. Find the number of student tickets and the number of nonstudent tickets the school sold.

6 Class work 1) s = # of drum sticks 2) m = # of lawns mowed b = # of drum brushes s = # of drive ways shoveled 10.50s + 24b = m + 200s = 2600 s = 2b 12 = m + s 3) 4) b = # of blooming plants n = # of non blooming plants 3.20b n = b + n = 24 i = # of infield outs o = # of outfield outs o + i = 27 o +.25i = 12

7 1 2 wkst 3 4 Math Geek! Math Geek!

8 Lesson: 7.2 day 2 Date: LT#3: substitution = I can solve a system by substitution. nbp.3 Steps to solve a system by substitution = step 1: step 2: step 3: Example:1 Solve the system. (substitution) y = 3x + 2 x + 2y = 11 Example:2 Solve the system. (substitution) x 2y = 6 4x + 6y = 4 Summary The answer to a Linear System is an ORDERED PAIR (x,y).

9 Class work 1) Complete 1 4 (worksheet) 2) Check answers 1 (19,16) 3) Raise hand (Spaeth) pink sheet 4) Start HW 2 (20,40) 3 (20,12) 4 (5, 7.50)

10 7.2 CW Your school is selling football tickets for a home game. The school sold 35 tickets for $86 on the first day of the sale. Student tickets cost $2 each and non student tickets cost $3 each. Find the number of student tickets and the number of non student tickets the school sold. 1. s = n = Solve each problem using the substitution method.

11 7.2 CW Solve each problem using the substitution method. 2. You burned 8 calories per minute on a treadmill and 10 calories per minute on an elliptical trainer for a total of 560 calories in 60 minutes. How many minutes did you spend on each machine? t = e =

12 7.2 CW 3. l = s = Solve each problem using the substitution method. As the student council treasurer, you prepare the budget for your class rafting trip. Each large raft costs $100 to rent, and each small raft costs $40 to rent. If you rent 32 rafts and spend $2480, how many large and small rafts did you rent for the trip?

13 4. Sam is going to the state fair. She has two ticket options as shown in the table. Write an equation that shows the cost per person for each option. Then use substitution to solve the system of equations. r = # of rides t = total cost Raise hand (Spaeth) pink sheet

14 HW 7.2 day 2 p.439(1,5,11,17,19,21,23,26,31-32)

15 HW 7.2 day 2 p.439(1,5,11,17,19,21,23,26,31-32) 26) (5.5, 9) 32) 22 tubes for a person and 4 'cooler' tubes