Solving linear equations is a fundamental skill in algebra, but students often make mistakes that lead to incorrect solutions. Here are some common mistakes and how to fix them:
1. Incorrectly Combining Like Terms
Mistake:
Students sometimes add or subtract terms that are not like terms.
Example:
→ (Incorrectly combining and )
Fix:
Only combine terms with the same variable (or constants).
Correct Step:
→
2. Misapplying the Distributive Property
Mistake:
Forgetting to multiply all terms inside the parentheses.
Example:
→ (Forgot to multiply by )
Fix:
Multiply every term inside the parentheses by the outside factor.
Correct Step:
3. Sign Errors When Moving Terms
Mistake:
Forgetting to change the sign when moving terms across the equals sign.
Example:
→ (Should be )
Fix:
When moving terms, reverse the sign:
Correct Step:
→
4. Dividing Incorrectly (Especially Negative Signs)
Mistake:
Dividing only one side or mishandling negative signs.
Example:
→ (Forgot to divide both sides by )
Fix:
Always divide both sides by the coefficient of .
Correct Step:
5. Not Simplifying Before Solving
Mistake:
Trying to solve without simplifying both sides first.
Example:
→ Complicated approach instead of simplifying.
Fix:
First, combine like terms on each side.
Correct Step:
→
6. Forgetting to Check the Solution
Mistake:
Assuming the answer is correct without verifying.
Example:
Solving → , but not plugging back in to check.
Fix:
Always substitute the solution back into the original equation.
Verification:
→ (Valid!)
Key Takeaways to Avoid Mistakes:
✅ Combine only like terms (same variable or constants).
✅ Apply the distributive property correctly (multiply all terms inside).
✅ Flip signs when moving terms across the equals sign.
✅ Divide both sides properly (especially with negatives).
✅ Simplify first before solving.
✅ Always check your solution by substitution.