Question Detail
Question
Find the sixth term in the expansion of \( (2x + 5y/2)^9 \).
Correct Answer
Option C is the correct answer.
Detailed Explanation
The general term is T_{r+1} = C(9, r) (2x)^{9-r} (5y/2)^r. For the sixth term, r=5. T_6 = C(9,5) (2x)^4 (5y/2)^5 = 126 * (16 x^4) * (3125 y^5 / 32) = 126 * 16 * 3125 / 32 * x^4 y^5 = 126 * (16/32) * 3125 * x^4 y^5 = 126 * (1/2) * 3125 * x^4 y^5 = 63 * 3125 * x^4 y^5 = 196875 x^4 y^5.
Hint
Apply the binomial theorem carefully, simplifying the coefficients and exponents.