Edexcel C1 2009 January — Question 3 2 marks

Exam BoardEdexcel
ModuleC1 (Core Mathematics 1)
Year2009
SessionJanuary
Marks2
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicIndices and Surds
TypeExpand and simplify surd expressions
DifficultyEasy -1.8 This is a straightforward application of the difference of two squares formula (a+b)(a-b) = a²-b², requiring only basic surd manipulation to get 7-4=3. It's a single-step routine exercise with minimal computational demand, significantly easier than average A-level questions.
Spec1.02b Surds: manipulation and rationalising denominators

Expand and simplify \(( \sqrt { } 7 + 2 ) ( \sqrt { } 7 - 2 )\).

Question 3:
AnswerMarks Guidance
\(\sqrt{7}^2 + 2\sqrt{7} - 2\sqrt{7} - 2^2\), or \(7-4\), or exact equivalent such as \(\sqrt{49}-2^2\)M1 Expanded expression with at most one wrong term and one wrong sign, or two wrong signs.
\(= 3\)A1 Correct answer with no working scores both marks. ([2] total)
## Question 3:

$\sqrt{7}^2 + 2\sqrt{7} - 2\sqrt{7} - 2^2$, or $7-4$, or exact equivalent such as $\sqrt{49}-2^2$ | M1 | Expanded expression with at most one wrong term and one wrong sign, or two wrong signs.

$= 3$ | A1 | Correct answer with no working scores both marks. (**[2]** total)

---
Expand and simplify $( \sqrt { } 7 + 2 ) ( \sqrt { } 7 - 2 )$.\\

\hfill \mbox{\textit{Edexcel C1 2009 Q3 [2]}}