Higher November 2021 Unit 1 Q10
10. Express \(\dfrac{5x}{2x - 1} - \dfrac{4x}{4x + 3}\) as a single fraction in its simplest form. [4]
| Scheme | Marks | Comments |
|---|---|---|
| Sight of \(20x^2 + 15x - 8x^2 + 4x\) or equivalent. | B2 | Award B1 for sight of \(5x(4x + 3) - 4x(2x - 1)\) OR three of the four terms correct. |
| Sight of denominator of \((2x - 1)(4x + 3)\) | B1 | Must be seen or stated as the denominator. |
| \(\dfrac{12x^2 + 19x}{(2x - 1)(4x + 3)}\) or \(\dfrac{12x^2 + 19x}{8x^2 + 2x - 3}\) | B1 | FT from one error in numerator. Note the numerator may be factorised as \(x(12x + 19)\) Mark final answer. |