4MA0 Higher June 2013 Paper 4R Q9
9

Diagram NOT accurately drawn
In the isosceles triangle \(ABC\),
\(AB = AC\)
angle \(B = (3x + 32)^\circ\)
angle \(C = (87 - 2x)^\circ\)
Work out the value of \(x\).
Show clear algebraic working.
(4)
| Scheme | Marks |
|---|---|
| \(3x + 32 = 87 - 2x\) | M1 |
| \(5x = 55\) or \(5x - 55 = 0\) or \(5x = 87 - 32\) or \(3x + 2x = 55\) | M2 |
| 11 | A1 |
| (4) |
Notes
M1: for \(3x + 32 = 87 - 2x\)
M2: for correct rearrangement with \(x\) terms on one side and numbers on the other AND correct collection of terms on at least one side or for correct collection to 2 terms
M1 for correct rearrangement with \(x\) terms on one side and numbers on the other e.g \(3x + 2x = 87 - 32\) or correct collection and simplification of either numbers or \(x\) terms eg \(5x + 32 = 87\) or \(5x = a\) or \(bx = 55\)
A1: dependent on at least one M1