SOLUTION: find C(10,4)

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Question 222506: find C(10,4)
Answer by Edwin McCravy(20086) About Me  (Show Source):
You can put this solution on YOUR website!
C(10,4)

The formula is

C%28n%2Cr%29+=+n%21%2F%28r%21%28n-r%29%21%29

Substituting:



Cancel the 6%2A5%2A4%2A3%2A2%2A1s:



C%2810%2C4%29+=%2810%2A9%2A8%2A7%29%2F%284%2A3%2A2%2A1%29

Cancel the 4 and 2 in the bottom into 
the 8 on top

C%2810%2C4%29+=%2810%2A9%2Across%288%29%2A7%29%2F%28cross%284%29%2A3%2Across%282%29%2A1%29

C%2810%2C4%29+=%2810%2A9%2A7%29%2F%283%2A1%29

Cancel the 3 in the bottom into the 9 on top leaving 3 on top:

        3
C%2810%2C4%29+=%2810%2Across%289%29%2A7%29%2F%28cross%283%29%2A1%29

C%2810%2C4%29+=%2810%2A3%2A7%29%2F%281%29

C%2810%2C4%29=210

Edwin