Grade 9 Math · Algebra
Lesson 2.3
Solving Linear Equations
Isolate a variable using inverse operations, and check that a solution is reasonable.
Estimated time: 30–45 minutes
Lesson progress0%
Learning goals
- I can solve one-step and two-step linear equations.
- I can check my solution by substituting it back in.
Step 1 of 2
Learn
The idea, explained clearly — with the words mathematicians use.
Keep the equation balanced
Whatever you do to one side of an equation, do to the other side too. That keeps both sides equal.
- Inverse operation
- An operation that undoes another operation.
Curriculum connection
These are the words your teacher and the Ontario curriculum use. Learn them here and use them when you explain your thinking.
- Curriculum languageInverse operation
- What this meansAn inverse operation undoes another operation. Subtraction undoes addition, and division undoes multiplication.
Step 2 of 2
Mastery Check
Show what you can do now that you could not do at the start.
You have finished this lesson
- I can solve one-step and two-step linear equations.
- I can check my solution by substituting it back in.
A unit check is waiting at the end of Algebra.