| Exam Board | Edexcel |
|---|---|
| Module | C1 (Core Mathematics 1) |
| Marks | 4 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Indices and Surds |
| Type | Show surd expression equals value |
| Difficulty | Easy -1.2 This is a straightforward surd simplification question requiring students to simplify √12 and √75 into surd form, combine like terms, then identify the resulting value. It's a standard C1 exercise testing basic surd manipulation with no problem-solving required, making it easier than average but not trivial since it requires multiple steps of simplification. |
| Spec | 1.02b Surds: manipulation and rationalising denominators |
| Answer | Marks | Guidance |
|---|---|---|
| \(4\sqrt{12} - \sqrt{75} = 4(2\sqrt{3}) - 5\sqrt{3} = 3\sqrt{3}\) | M1 A1 | |
| \(= \sqrt{9 \times 3} = \sqrt{27}\), \(n = 27\) | M1 A1 | (4) |
$4\sqrt{12} - \sqrt{75} = 4(2\sqrt{3}) - 5\sqrt{3} = 3\sqrt{3}$ | M1 A1 |
$= \sqrt{9 \times 3} = \sqrt{27}$, $n = 27$ | M1 A1 | (4)\begin{enumerate}
\item Find the integer $n$ such that
\end{enumerate}
$$4 \sqrt { 12 } - \sqrt { 75 } = \sqrt { n }$$
\hfill \mbox{\textit{Edexcel C1 Q3 [4]}}