Exam-style question
Try this first
Why must an inequality involving a fraction identify excluded values before giving the solution?.
- A.B5: justify each step using the relevant algebra and functions rule
- B.Use any familiar GCSE calculation even if it ignores solving linear and quadratic inequalities in a single variable…
- C.Write only the final answer without showing the mathematical method
- D.Change the notation or restrictions to make the algebra look simpler
Model answer
What a good answer should say
- The correct answer is B5: justify each step using the relevant algebra and functions rule.
- Values that make a denominator zero are excluded because the expression is undefined there, even if they appear during algebraic rearrangement.
This answer is tied to the objective: B5 Solve linear and quadratic inequalities in a single variable and interpret such inequalities graphically, including inequalities with brackets and fractions; express solutions through correct use of and and or, or through set notation; represent linear and quadratic inequalities graphically..
Explanation
Why this works
Use the explanation to connect the worked answer back to B5 Solve linear and quadratic inequalities in a single variable and interpret such inequalities graphically, including inequalities with brackets and fractions; express solutions through correct use of and and or, or through set notation; represent linear and quadratic inequalities graphically..
The correct option, B5: justify each step using the relevant algebra and functions rule, is supported because fractional inequalities require attention to undefined values and sign changes. Multiplying by an expression with unknown sign without splitting cases can reverse or distort the inequality.
Maths method check
- Topic focus: Pure Mathematics.
- Question style: practice.
- Reasoning demand: understanding.
- Check the operation, notation, units, and final answer form against the question before moving on.
Common mistake
No common mistake is linked to this question yet.