If $216x^3+\frac{1}{125}=\left(6x+\frac{1}{5}\right)\left(36x^2-kx+\frac{1}{25}\right)$, find the value of $k$. (write the answer in fraction form)

Factorization of $16x^4+54x$ is $(4x^2+kx)\left(4x^2-kx+9\right)$. Then find the value of $k$.

Factorization of $7a^3+56b^3$ is $7(a+kb)\left(a^2-kab+4b^2\right)$. Then find the value of k.

Factorization of $x^5+x^2$ is $x^2(x+1)\left(x^2-x+k\right)$. Then find the value of k.

Factorization of $a^3+0.008$ is $(a+0.2)\left(a^2-0.2a+k\right)$. Then find the value of k.

Factorization of $1-27a^3$ is $(k-3a)\left(k+3a+9a^2\right)$. Then find the value of $k$

Factorization of $64a^3-343$ is $(4a-7)\left(16a^2+28a+k\right)$. Then find the value of $k$.

Factorization of $x^3-512$ is $(x-k)\left(x^2+kx+64\right)$. Then find the value of k.

Factorization of $a^3-0.064$ is $(a-k)\left(a^2+ka+0.16\right)$. Then find the value of k.