Pre-Algebra Lesson
Breaking Apart Absolute Value: Solving |ax + b| = c
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7th — Level II (College Prep)BTC Style / Thinking Classrooms40 min
Learning Objective
Students will solve absolute value equations of the form |ax + b| = c by writing and solving two linear equations derived from the definition of absolute value.
Lesson Overview
Students progress from interpreting absolute value on a number line to solving multi-step absolute value equations, discovering that each equation splits into two separate cases.
Materials
- Vertical whiteboards or chart paper
- Dry-erase markers (multiple colors)
- Erasers or paper towels
- Random grouping tool
- Number line reference strips (optional)
Scaffolded Task Progression
1Task 1
Use the number line below to answer: What values of make true? Mark BOTH solutions on the number line and write the two equations.
[ Interactive graph / diagram, available in the full lesson ]
[ Interactive graph / diagram, available in the full lesson ]
2Task 2
Solve:
Write the two-case split, solve each case, and check both answers by substituting back into the original equation.
Write the two-case split, solve each case, and check both answers by substituting back into the original equation.
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