+1678 How do I solve this?
What is the constant term of the expansion of \(\left( 6x + \frac{3}{x} \right)^4\)?
+1223 The general term is \(\binom{4}{n}(6x)^{n}(\frac{3}{x})^{4-n}\). For the 6x and 3/x terms to balance out, n must equal 2.
\(\binom{4}{2} (6x)^2 (\frac{3}{x})^2 = 6 \cdot 36x^2 \cdot \frac{9}{x^2} = \boxed{1944}.\)
