In the expansion of $\left(1+\dfrac{2}{x}\right)^8$, the coefficient of $\dfrac{1}{x^2}$ is —

Question

Accepted Answer

$112$

Answer

$56$

Answer

$84$

Answer

$128$

In the expansion of (1+2x)8\left(1+\dfrac{2}{x}\right)^8(1+x2​)8, the coefficient of 1x2\dfrac{1}{x^2}x21​ is —