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