Algebra lesson

Solving linear equations with inverse operations.

An equation is a balanced scale. Whatever you do to one side, you do to the other so the two sides stay equal.

Example

Solve 2x + 5 = 17. Subtract 5 from both sides: 2x = 12. Divide both sides by 2: x = 6. Check: 2(6)+5 = 17. The check is not optional; it is how you know the scale still balances.

Your turn

Solve 3x − 4 = 11. Write every inverse step. Then check by substitution. If your check fails, look for a sign error on the constant term — the most common classroom miss.