Alg1 Lesson 2.3.2: Substitution & Elimination

Lesson 2.3.2: Substitution &

Elimination

Obj: 5C (5A, 5B) I can solve systems of 2 linear
equations using elimination and substitution.

EQ: When is it better to use elimination vs
substitution?

Roles:
Facilitator
Scribe
Resourcer
Includer

Lesson Goals:
● Creative Thinking
● Talk through controversies and conflict
● Recognize and reduce ambiguity
● Encourage thinking based on formulas and prior info
● Help explain ideas to each other
● Own your ideas and work
● Record ideas in your journal
● Answer Questions on Slides
● Follow your team roles

Facilitator

• Make sure that all peers are staying on task.

• Give advice or suggestions to resolve the problem.

• Be sure everyone is able to explain.

Scribe

• Make sure peers organize their results on their own papers.

• Remind peers to use color, arrows, and other math tools to
communicate your mathematics, reasons, and connections.

• Be ready to join the teacher for a huddle.

Resourcer

• Make sure peers are getting the materials needed.

• Make sure that all materials are put away neatly.

• Make sure that peers are logged in to the needed site.

• Help troubleshoot any technology difficulties that may arise.

Includer

• Make sure that all peers are talking about their work.

• Helps keep peers’ voice volume low.

• Encourages everyone to ask questions.

• Communicates conflicts or questions to the teacher.

● Check off tasks & skills on calendar.

● Select skills to work on.

● Work on Deltamath.

Remember to work on the following too…

Part 1: Foldable 5C

Foldable 5C

Go to
https://www.youtube.com/watch?v=r5wmxMJeZWY&list=PLLGOjBzu8kWejUlKz8Zk8VhLSJ-5X4Gi8&index=39
for Foldable 5C. Glue the foldable into your
journal. It will be part of your next journal check.

Part 2: WS 3.2.1

Substitution

Show work and turn in physical worksheet too.

Multiple Choice

Solve the system using substitution.

y=-2x+3 and 5x+2y=4

Solution:

• (-2, 7)
• (1, 1)

• (4, -8)

• (0, 3)

• (3, -3)

Fill in the Blank

Solve the system using substitution.

y=3x-2 and y=7x+2

Solution:

(

-

,

-

)

Random Question of the Day Time

https://wheelofnames.com/4ke-epz We’ll spin
the wheel as a class and spend a minute or so
discussing our answers.

Part 3: WS 3.2.2:

Elimination

Show work and turn in physical worksheet too.

Multiple Choice

Solve using elimination.

-3x+y=6 and 7x-y=2

• (1, 3)
• (0, 6)
• (3, 9)
• (2, 12)
• (1, 9)

Fill in the Blank

Solve using elimination.

9x+3y=33 and 5x-2y=0

Solution:

(

,

)

Poll

Which method do you like to do better?

• Substitution

• Elimination