Easy -1.2 This is a straightforward application of the binomial theorem requiring identification of the correct term and simple calculation. It's easier than average as it involves only one step (finding one coefficient) with small numbers, though students must handle the negative sign correctly.
B2 for 15 or \(5 \times (-3)^1\) or better; OR B1 for 5 or 1 5 10 10 5 1 row of Pascal's triangle seen. Do not accept \(_5C_4\) as a correct element without evaluation to 5
**Question 2:**
$-15$ | **B3** | **B2** for 15 or $5 \times (-3)^1$ or better; **OR B1** for 5 or 1 5 10 10 5 1 row of Pascal's triangle seen. Do not accept $_5C_4$ as a correct element without evaluation to 5 | [3 marks total]
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