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Question
Find the middle term in the expansion of:
(ii) \[\left( \frac{a}{x} + bx \right)^{12}\]
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Solution
(ii) Here,
n = 12 (Even number)
Therefore, the middle term is the
\[ T_7 = T_{6 + 1} \]
\[ =^{12}{}{C}_6 \left( \frac{a}{x} \right)^{12 - 6} (bx )^6 \]
\[ = ^{12}{}{C}_6 a^6 b^6 \]
\[ = \frac{12 \times 11 \times 10 \times 9 \times 8 \times 7}{6 \times 5 \times 4 \times 3 \times 2} a^6 b^6 \]
\[ = 924 a^6 b^6\]
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