Moderate -0.5 This is a straightforward binomial expansion requiring identification of the correct term where powers of x sum to 1. It's slightly easier than average as it's a single-step problem with clear method (general term formula), though students must handle negative powers carefully.
Can be implied or in the expansion. Co. If all expansion given, gets \(\frac{3}{4}\) unless required term is isolated from expansion or ringed
\(\rightarrow 1080\)
B1
[4]
## Question 1: $(3x - 2/x)^5$
| Answer/Working | Marks | Guidance |
|---|---|---|
| Required term has $_5C_2$ or $_5C_3 = 10$ | B1 | Needs 10 or implied by answers |
| Also has $3^3$ and $2^2$ | B1 B1 | Can be implied or in the expansion. Co. If all expansion given, gets $\frac{3}{4}$ unless required term is isolated from expansion or ringed |
| $\rightarrow 1080$ | B1 | [4] |
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