What is the coefficient of the middle term in the binomial expansion of (2 + 3x)⁴ ?

Let the coefficient of the middle term of the binomial expansion of (1 + x)²ⁿ be $$\alpha$$ and those of two middle terms of the binomial expansion of (1 + x)^{2n $$-$$ 1} be $$\beta$$ and $$\gamma$$. Which one of the following relations is correct?

In the expansion of (1 + x)⁴³, if the coefficients of (2r + 1)th and (r + 2)th terms are equal, then what is the values of r(r $$\ne$$ 1) ?

If the coefficients of a^m and aⁿ in the expansion of (1 + a)^{m + n} are $$\alpha$$ and $$\beta$$, then which one of the following is correct?