\(=\dfrac{1}{x\left(1-5x\right)}+\dfrac{25x-15}{\left(1-5x\right)\left(1+5x\right)}\)
\(=\dfrac{1+5x+25x^2-15x}{x\left(1-5x\right)\left(1+5x\right)}\)
\(=\dfrac{\left(1-5x\right)^2}{x\left(1-5x\right)\left(1+5x\right)}=\dfrac{1-5x}{x\left(1+5x\right)}\)