4024/12 May/Jun 2025, Question 15: Surds
Cambridge O Level Mathematics 4024 · Paper 12 (Non-calculator) · Non-calculator · 3 marks
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The question, in short
Simplify the surd expression √175 − √28, then rationalise the denominator of 1/√5.
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Part (a) · 2 marks
Simplify √175 − √28, giving the answer in simplest surd form.
- 1√175 = √25 × √7 = 5√7
- 2√28 = √4 × √7 = 2√7
- 35√7 − 2√7 = 3√7
Answer3√7
Part (b) · 1 mark
Rationalise the denominator of 1/√5.
- 11/√5 × √5/√5 = √5/5
Answer√5/5
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Also searched as: 4024/12/M/J/25 · 4024_s25_qp_12 · 4024 s25 12 · question 15.
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