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# Mistake in markscheme? watch

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1. C2 Solomon paper A markscheme for question 4 on the binomial expansion.

It says expand (1 + 3x)^8 in ascending powers of x up to and including the term in x^3. You should simplify each coefficient in your expansion.

Ok so:

1 + 8(3x) + [8C2] (3x)^2 + [8C3] (3x)^3......

the markschemes says its 1 + 24x + 252x^2 + 1512x^3
But when i use my calculator [8C2] gives me 28 and times that by 3 doesnt equal 252?

Can someone please correct me if im wrong

2. That's because it's *3^2.
3. 3^2, not 3.
4. w00t 1500 congrats. dvs.
5. oh right, thanks a lot

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Updated: April 7, 2006
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