Higher November 2021 Unit 1 Q12
12. Rearrange the following formula to make \(w\) the subject.
\(xw + 4 = 3y - 8w\) [3]
| Scheme | Marks | Comments |
|---|---|---|
| \(xw + 8w = 3y - 4\) or \(4 - 3y = -\,xw - 8w\) | B1 | Collecting \(w\) terms. F.T. until 2nd error provided equivalent difficulty |
| \(w\,(\,x + 8\,) = 3y - 4\) or \(4 - 3y = w\,(\,-\,x - 8\,)\) | B1 | Factorising. Accept \(4 - 3y = -\,w\,(\,x + 8\,)\) |
| \(w = \dfrac{3y - 4}{x + 8}\) or \(w = \dfrac{4 - 3y}{-\,x - 8}\) or equivalent | B1 | Dividing. Mark final answer. \(\dfrac{4 - 3y}{x + 8} = -w\) only gains B1B1B0 |