Higher November 2024 Paper 2 Q17
17 Show that \(\dfrac{6x - y}{10xy} + \dfrac{1}{2x} - \dfrac{2y - 7x}{5xy}\) simplifies to \(\dfrac{k}{y}\) where \(k\) is an integer. (3)
| Answer | Mark | Mark scheme |
|---|---|---|
| shown | M1 | for use of a common denominator for 2 correct fractions, eg 2 of \(\dfrac{6x - y}{10xy}\) or \(\dfrac{5y}{10xy}\) or \(\dfrac{2(2y - 7x)}{10xy}\) oe |
| M1 | for a correct method to write as single fraction, eg \(\dfrac{6x - y}{10xy} + \dfrac{5y}{10xy} - \dfrac{4y - 14x}{10xy}\) or \(\dfrac{6x - y}{10xy} + \dfrac{5y}{10xy} - \dfrac{(4y - 14x)}{10xy}\) or \(\dfrac{6x - y + 5y - 4y + 14x}{10xy}\) or \(\dfrac{20x}{10xy}\) oe | |
| C1 | for correct working leading to \(\dfrac{2}{y}\) |
Additional guidance
If seen in steps all arithmetic must be correct