SOLUTION: What is the fourth term in the expansion of (x + 4y)^4?

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Question 1082744: What is the fourth term in the expansion of (x + 4y)^4?
Found 2 solutions by MathLover1, MathTherapy:
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

%28x+%2B+4y%29%5E4
%28x+%2B+4y%29%5E2%2A%28x+%2B+4y%29%5E2
%28x%5E2+%2B+8xy+%2B16y%5E2%29%2A%28x%5E2+%2B+8xy%2B+16y%5E2%29
x%5E4+%2B+16x%5E3%2Ay+%2B+96x%5E2%2Ay%5E2+%2B+256xy%5E3+%2B+256y%5E4
the fourth term in the expansion 256xy%5E3+

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

What is the fourth term in the expansion of (x + 4y)^4?
%28x+%2B+4y%29%5E4

To find a SPECIFIC TERM of a binomial expansion, we use the formula: , where: 

                                                                      r = 4

                                                                      n = 4

                                                                      a = x

                                                                      b = 4y

We then get: 4th term of  ======> %22%22%5B4%5DC%5B3%5D%28x%29%5E1%284y%29%5E3 ======> highlight_green%28matrix%281%2C3%2C+4x+%2A+64y%5E3%2C+%22=%22%2C+256xy%5E3%29%29