SOLUTION: find the fifth term in the binomial expansion of (2x - y)^6

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Question 229757: find the fifth term in the binomial expansion of (2x - y)^6
Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
find the fifth term in the binomial expansion of (2x - y)^6

The Rth term of %28A%2BB%29%5EN is given by
this expression:

%28matrix%282%2C1%2CN%2CR-1%29%29A%5E%28N-R%2B1%29B%5E%28R-1%29

where %28matrix%282%2C1%2Cp%2Cq%29%29 means the same as C%28p%2Cq%29 or pCq 

In your problem A=2x, B=-y, N=6, R=5

So we substitute those and get

 %28matrix%282%2C1%2C6%2C5-1%29%29%282x%29%5E%286-5%2B1%29%28-y%29%5E%285-1%29

%28matrix%282%2C1%2C6%2C4%29%29%282x%29%5E%282%29%28-y%29%5E%284%29

%2815%29%284x%5E2%29%28y%5E4%29

60x%5E2y%5E4

Edwin