OCR MEI C1 2009 January — Question 9 4 marks

Exam BoardOCR MEI
ModuleC1 (Core Mathematics 1)
Year2009
SessionJanuary
Marks4
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicSolving quadratics and applications
TypeRearranging formula - variable appears multiple times
DifficultyModerate -0.8 This is a straightforward algebraic rearrangement requiring expansion, collection of y terms, and factorization. While it involves a quadratic structure, it's simpler than typical C1 questions as it requires only basic algebraic manipulation with no problem-solving insight needed.
Spec1.02c Simultaneous equations: two variables by elimination and substitution

9 Rearrange \(y + 5 = x ( y + 2 )\) to make \(y\) the subject of the formula.

Question 9:
AnswerMarks Guidance
Answer/WorkingMark Guidance
\(y + 5 = xy + 2x\)M1 for expansion
\(y - xy = 2x - 5\) oe or ftM1 for collecting terms
\(y(1 - x) = 2x - 5\) oe or ftM1 for taking out \(y\) factor; dep on \(xy\) term
\(y = \frac{2x-5}{1-x}\) oe or ft as final answerM1 for division and no wrong work after; ft earlier errors for equivalent steps if error does not simplify problem
Total: 4 marks
# Question 9:

| Answer/Working | Mark | Guidance |
|---|---|---|
| $y + 5 = xy + 2x$ | M1 | for expansion |
| $y - xy = 2x - 5$ oe or ft | M1 | for collecting terms |
| $y(1 - x) = 2x - 5$ oe or ft | M1 | for taking out $y$ factor; dep on $xy$ term |
| $y = \frac{2x-5}{1-x}$ oe or ft as final answer | M1 | for division and no wrong work after; ft earlier errors for equivalent steps if error does not simplify problem |
| **Total: 4 marks** | | |

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9 Rearrange $y + 5 = x ( y + 2 )$ to make $y$ the subject of the formula.

\hfill \mbox{\textit{OCR MEI C1 2009 Q9 [4]}}