Which expression represents the sixth term in the binomial expansion of open paren 5 y plus 3 close paren to the 10th power ?

The general term in (a + b)^10 is ₁₀Cᵣ(5y)^(10−r)3ʳ, where r starts at 0 for the first term. The sixth term uses r = 5, giving ₁₀C₅(5y)^5 3^5. This matches choice A, written as ₁₀C₅ 5^5y^5 3^5.

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