To add or subtract expressions, expand them to make their denominators the same. Least common multiple of $x^{2}$ and $x$ is $x^{2}$. Multiply $\frac{4\left(5x^{2}-1\right)}{x}$ times $\frac{x}{x}$.
Since $\frac{\left(5x^{2}-1\right)^{2}}{x^{2}}$ and $\frac{4\left(5x^{2}-1\right)x}{x^{2}}$ have the same denominator, add them by adding their numerators.
To add or subtract expressions, expand them to make their denominators the same. Least common multiple of $x^{2}$ and $x$ is $x^{2}$. Multiply $\frac{4\left(5x^{2}-1\right)}{x}$ times $\frac{x}{x}$.
Since $\frac{\left(5x^{2}-1\right)^{2}}{x^{2}}$ and $\frac{4\left(5x^{2}-1\right)x}{x^{2}}$ have the same denominator, add them by adding their numerators.