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Question
Find the middle term in the expansion of `(2ax - b/x^2)^12`.
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Solution
Since the power of binomial is even, it has one middle term which is the `(12 + 2)^"th"/2` term and it is given by
T7 = `""^12"C"_6 (2ax)^6 ((-b)/x^2)^6`
= `""^12"C"_6 (2^6 a^6 x^6 * (-b)^6)/x^12`
= `""^12"C"_6 (2^6 a^6 b^6)/x^6`
= `(59136a^6b^6)/x^6`
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