Which set of coefficients of the terms in the expansion of the binomial (x + y)^3 is correct? 1, 3, 3, 1 1, 4, 4, 1 1, 2, 2, 1 1, 5, 5, 1

 The answer is 1 3 3 1 

The coefficients of the expanded terms are a combination; 4C1 , 4C2, 4C3, 4C4 multiplied by the x, y coefficients in the parenthesis. Since x, y coefficients in parenthesis is 1 the expanded coefficients are just the combinations.

4C1 = 1
4C2 = 3
4C3 = 3
4C4 = 1

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