Activity
Your teacher will give you a set of cards. Take turns with your partner to match a group of 4 cards that contain: a situation, an inequality that represents it, a graph that represents the solution region, and a solution written as a coordinate pair.
For each match that you find, explain to your partner how you know it's a match.
For each match that your partner finds, listen carefully to their explanation. If you disagree, discuss your thinking and work to reach an agreement.
Record your matches.
Group 1
- situation: perimeter of a rectangle
- inequality:
- a solution:
- sketch of graph:
Group 2
- situation: jar of coins
- inequality:
- a solution:
- sketch of graph:
Group 3
- situation: honey and jam
- inequality:
- a solution:
- sketch of graph:
Group 4
- situation: a school trip
- inequality:
- a solution:
- sketch of graph:
Compare your answer: Your answer may vary, but here is a sample.
Group 1 - situation: perimeter of a rectangle Group 2 - situation: jar of coins
Group 3 - situation: honey and jam Group 4 - situation: a school trip
Self Check
Additional Resources
Connecting Representations of Inequalities
In order to connect the constraints of a situation with an inequality, its graph, and possible solutions, we need a mastery of each representation.
Example
Christy sells her photographs at a booth at a street fair. Each small photo she displays costs her $4 and each large photo costs her $10. She doesn’t want to spend more than $200 on photos to display.
Let be the number of small photos and be the number of large photos that Christy displays.
We know that each small photo costs $4 to display and each large photo costs $10. We also know that she doesn’t want to spend more than $200.
The inequality that represents this situation is .
To be able to connect this inequality with possible solutions, translating it into a graph is an important step.
Try it
Try It: Connecting Representations of Inequalities
Graph the linear inequality: .
Compare your answer:
Is it possible for Christy to display 15 small paintings and 15 large paintings and maintain her budget of $200?
Compare your answer:
No; the ordered pair does not fall within the region representing the solution. Another way to verify this is by using the inequality.
Since $210 is not less than $200, 15 small paintings and 15 large paintings does not stay with Christy’s budget of $200.