SOLUTION: Please help me solve this problem: What is the coefficient of x^7 in (3 + x)^12

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Question 846062: Please help me solve this problem: What is the coefficient of x^7 in (3 + x)^12
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Use Pascal's triangle.
The coefficients would be
x%5E12+-+1
x%5E11+-12
x%5E10+-66
x%5E9+-220
x%5E8+-495
x%5E7-792
x%5E6-924
x%5E5-792
x%5E4-495
x%5E3-220
x%5E2-66
x%5E1-12
x%5E0-1