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Given (x+y)^12, find the coefficient of the 7th term.

200
495
792
924

User LightBox
by
3.3k points

2 Answers

3 votes

Answer:

924

Explanation:

User Tomol
by
3.4k points
4 votes

Answer: 924

Explanation:

1. Use the combination formula nCr = n!/(n-r)!r!

Using this formula gets you 16 (n) C 6 (r) = 12!/6!6! Which is also 12 • 11 • 10 • 9 • 8 • 7 • 6 • 5 • 4 • 3 • 2 • 1 / 6 • 5 • 4 • 3 • 2 • 1 • 6 • 5 • 4 • 3 • 2 • 1

2. Cancel out matching multiples that are in the numerator and denominator

This gets you 12 • 11 • 10 • 9 • 8 • 7 / 6 • 5 • 4 • 3 • 2 • 1 or 665280/720 when you simplify which leads you to the answer 924

Hope this helps!

User Sergey Tyupaev
by
3.8k points