Coefficient of $x^2$ in $(x+\frac 2x)^6$ I did $6C4 x^2\times (\dfrac 2x)^4$ and got that the coefficient of $x^2$ is $15$, but the answer is $60$, why? Did I miss a step?

It's much easier [for me] to see where the $x^2$ terms are after rewriting:    $$(x + \dfrac{2}{x})^6 = (\dfrac{x^2 + 2}{x})^6 = \dfrac{1}{x^6}(x^2 +2)^6$$
Then we only have $x^2$ terms where the expansion of the binomial gives $x^8$ (because we're dividing everything by $x^6$). That term is $15(x^2)^4 \cdot 2^2$.
