Numerically greatest term in the expansion of $(5+3 x)^6$ When, $x=1$, is

The square root of independent term in the expansion of $ \left( 2x^2 + \frac{5}{x} \right)^5 $ is

The coefficient of $x^5$ in $\left(3+x+x^2\right)^6$ is

The absolute value of the difference of the coefficients of $x^4$ and $x^6$ in the expansion of $x^2 - 2x^2 + (x + 1)^4(x^2 - 1)^2$, is