To add or subtract expressions, expand them to make their denominators the same. Least common multiple of $2\left(x-2\right)\left(x+1\right)$ and $4\left(x-2\right)\left(x+4\right)$ is $4\left(x-2\right)\left(x+1\right)\left(x+4\right)$. Multiply $\frac{3x}{2\left(x-2\right)\left(x+1\right)}$ times $\frac{2\left(x+4\right)}{2\left(x+4\right)}$. Multiply $\frac{x-1}{4\left(x-2\right)\left(x+4\right)}$ times $\frac{x+1}{x+1}$.
Since $\frac{3x\times 2\left(x+4\right)}{4\left(x-2\right)\left(x+1\right)\left(x+4\right)}$ and $\frac{\left(x-1\right)\left(x+1\right)}{4\left(x-2\right)\left(x+1\right)\left(x+4\right)}$ have the same denominator, subtract them by subtracting their numerators.
To add or subtract expressions, expand them to make their denominators the same. Least common multiple of $4\left(x-2\right)\left(x+1\right)\left(x+4\right)$ and $8\left(x+1\right)\left(x+4\right)$ is $8\left(x-2\right)\left(x+1\right)\left(x+4\right)$. Multiply $\frac{5x^{2}+24x+1}{4\left(x-2\right)\left(x+1\right)\left(x+4\right)}$ times $\frac{2}{2}$. Multiply $\frac{10x-1}{8\left(x+1\right)\left(x+4\right)}$ times $\frac{x-2}{x-2}$.
Since $\frac{2\left(5x^{2}+24x+1\right)}{8\left(x-2\right)\left(x+1\right)\left(x+4\right)}$ and $\frac{\left(10x-1\right)\left(x-2\right)}{8\left(x-2\right)\left(x+1\right)\left(x+4\right)}$ have the same denominator, subtract them by subtracting their numerators.
To add or subtract expressions, expand them to make their denominators the same. Least common multiple of $2\left(x-2\right)\left(x+1\right)$ and $4\left(x-2\right)\left(x+4\right)$ is $4\left(x-2\right)\left(x+1\right)\left(x+4\right)$. Multiply $\frac{3x}{2\left(x-2\right)\left(x+1\right)}$ times $\frac{2\left(x+4\right)}{2\left(x+4\right)}$. Multiply $\frac{x-1}{4\left(x-2\right)\left(x+4\right)}$ times $\frac{x+1}{x+1}$.
Since $\frac{3x\times 2\left(x+4\right)}{4\left(x-2\right)\left(x+1\right)\left(x+4\right)}$ and $\frac{\left(x-1\right)\left(x+1\right)}{4\left(x-2\right)\left(x+1\right)\left(x+4\right)}$ have the same denominator, subtract them by subtracting their numerators.
To add or subtract expressions, expand them to make their denominators the same. Least common multiple of $4\left(x-2\right)\left(x+1\right)\left(x+4\right)$ and $8\left(x+1\right)\left(x+4\right)$ is $8\left(x-2\right)\left(x+1\right)\left(x+4\right)$. Multiply $\frac{5x^{2}+24x+1}{4\left(x-2\right)\left(x+1\right)\left(x+4\right)}$ times $\frac{2}{2}$. Multiply $\frac{10x-1}{8\left(x+1\right)\left(x+4\right)}$ times $\frac{x-2}{x-2}$.
Since $\frac{2\left(5x^{2}+24x+1\right)}{8\left(x-2\right)\left(x+1\right)\left(x+4\right)}$ and $\frac{\left(10x-1\right)\left(x-2\right)}{8\left(x-2\right)\left(x+1\right)\left(x+4\right)}$ have the same denominator, subtract them by subtracting their numerators.