Warm Up I can solve systems of equations by substitution

Warm Up I can solve systems of equations by substitution

Warm Up I can solve systems of equations by substitution

Warm Up I can solve systems of equations by substitution Write a system of equations: Sara has 16 baseball cards and buys 7 more each week. Ted has 2 baseball cards and collects 9 more each week. Write a systems of equations and solve to find out when they will have the same number of cards.

Homework Questions

-8 xy xy x + y Diamond Problems 4

-42 3 xy xy x + y Diamond Problems

-4 12 xy xy x + y Diamond Problems

Solve by Graphing The solution isn’t at a clear point!

Try it! Try problems 1 and 2 on your practice sheet using the method we just discovered. See if you can solve the systems

Solving Systems with Substitution Steps 1.Determine variable to substitution 2.Make substitution 3.Solve

Solving Systems with Substitution Steps 4.Plug back into an original equation 5.Solve for missing variable 6.Write answer as a point

Practice 20 minutes Check your answers on the back table

Writing and Solving Systems April sold 75 tickets to a school play and collected a total of $495. If the adult tickets cost $8 each and child tickets cost $5 each, how many adult tickets and how many child tickets did she sell?

Define variables: System of equations: State your solution(s): Solve April sold 75 tickets to a school play and collected a total of $495. If the adult tickets cost $8 each and child tickets cost $5 each, how many adult tickets and how many child tickets did she sell? a = the number of adult tickets. c = the number of child tickets. a + c = 75 8a + 5c = 495 There were 40 adult tickets and 35 child tickets sold = 75 8(40) + 5(35) = = 495 a + c = 75 8a + 5c = 495 a = 75 – c 8(75 – c) + 5c = – 8c + 5c = c = = 3c 35 = c a + c = 75 a + 35 = 75 a = 40

Writing and Solving Systems At a baseball game, Jose bought four hot dogs and one soda for $12. At the same time, Allison bought two hot dogs and four sodas for $13. Find the cost of one hot dog and one soda.

Define variables: System of equations: State your solution(s): Solve At a baseball game, Jose bought four hot dogs and one soda for $12. At the same time, Allison bought two hot dogs and four sodas for $13. Find the cost of one hot dog and one soda. h = the price of hot dog. s = the price of a soda. 4h + s = 12 2h + 4s = 13 A hot dog costs $2.50 and a soda costs $ (2.5) + 2 = 12 2(2.5) + 4(2) = = 13 4h + s = 12 2h + 4s = 13 s = 12 – 4h 2h + 4(12 – 4h) = 13 2h + 48 – 16h = – 14h = = 14h 2.5 = h 4h + s = 12 4(2.5) + s = s = 12 s = 2

Textbook Homework