4MA0 Higher June 2011 Paper 3 Q5
5 Show that \(\dfrac{5}{6} - \dfrac{3}{4} = \dfrac{1}{12}\)
(2)
| Scheme | Marks |
|---|---|
| \(\frac{10}{12}\) and \(\frac{9}{12}\) eg \(\frac{10 - 9}{12}\), \(\frac{10}{12} - \frac{9}{12}\) | B2 |
| (Total 2 marks) |
Notes
B2: B1 for \(\frac{10}{12}\) or \(\frac{9}{12}\)
Also accept \(\frac{5 \times 2}{6 \times 2}\) or \(\frac{3 \times 3}{4 \times 3}\)
Alternative method
B1 for both fractions correctly expressed as equivalent fractions with denominators that are common multiples of 6 and 4 eg \(\frac{20}{24}\) and \(\frac{18}{24}\) or \(\frac{5 \times 4}{6 \times 4}\) and \(\frac{3 \times 6}{4 \times 6}\)
B1 (dep on first B1) for evaluation as a correct fraction which is equivalent to \(\frac{1}{12}\) eg \(\frac{2}{24}\)
SC B1 for multiplying both sides by 12 ie 10 − 9 = 1