Intermediate June 2018 Unit 2 Q9
9. The diagram below shows an equilateral triangle \(ABC\) with \(AB = (4x - 7)\) cm.
Diagram not drawn to scale
The perimeter of the triangle is 27 cm.
Calculate the value of \(x\). [3]
| Scheme | Marks | Comments |
|---|---|---|
| 3(4x – 7) = 27 or equivalent | M1 | M1 for 4x – 7 = 27/3 |
| 4x = 16 or 12x = 48 or equivalent | A1 | |
| x = 4 | A1 | FT from ax = b. Allow 3 marks for embedded answer BUT Only two marks if contradicted by ‘x ≠ 4’. Unsupported answer of x =4 gains all three marks. If no marks gained allow SC1 for sight of 9. |