OCR MEI C4 — Question 1 3 marks

Exam BoardOCR MEI
ModuleC4 (Core Mathematics 4)
Marks3
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicPartial Fractions
TypeSolve rational equation
DifficultyModerate -0.8 This is a straightforward rational equation requiring only algebraic manipulation: multiply through by x(x+1) to clear denominators, expand to get a quadratic, then solve. It's simpler than average A-level questions as it involves routine techniques with no conceptual depth or multi-step problem-solving.
Spec1.02k Simplify rational expressions: factorising, cancelling, algebraic division

1 Solve the equation. $$\frac { 8 } { x } - \frac { 9 } { x + 1 } = 1$$

Question 1:
AnswerMarks Guidance
Answer/WorkingMarks Guidance
\(\frac{8}{x} - \frac{9}{x+1} = 1\)M1
\(\Rightarrow 8(x+1) - 9x = x(x+1)\)A1
\(\Rightarrow 0 = x^2 + 2x - 8\)
\(\Rightarrow 0 = (x+4)(x-2)\)
\(\Rightarrow x = -4\) or \(2\)A1
Total: 3 marks
## Question 1:

| Answer/Working | Marks | Guidance |
|---|---|---|
| $\frac{8}{x} - \frac{9}{x+1} = 1$ | M1 | |
| $\Rightarrow 8(x+1) - 9x = x(x+1)$ | A1 | |
| $\Rightarrow 0 = x^2 + 2x - 8$ | | |
| $\Rightarrow 0 = (x+4)(x-2)$ | | |
| $\Rightarrow x = -4$ or $2$ | A1 | |
| **Total: 3 marks** | | |

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1 Solve the equation.

$$\frac { 8 } { x } - \frac { 9 } { x + 1 } = 1$$

\hfill \mbox{\textit{OCR MEI C4  Q1 [3]}}