Higher June 2017 Paper 3 Q12
12 \(\left(ar^b\right)^4 = 16r^{20} \quad\) where \(a\) and \(b\) are positive integers.
Work out \(a\) and \(b\) [2 marks]
| Answer | Mark | Comments |
|---|---|---|
| \(a = 2\) | B1 | May be embedded |
| \(b = 5\) | B1 | May be embedded |
Additional guidance
| \((2r^5)^4\) | B1B1 |
| \((r^5)^4\) | B1 |
| \(2^4 = 16\) on its own is not enough | B0 |
| \(a = 5\) and \(b = 2\) | B0B0 |