x(b + a)

x(1 + a)

$\frac{\textit{a}(\textit{x}+1)}{(\textit{x}+1)^{2}}$

$\frac{(\textit{x}+\textit{b})(\textit{x}-\textit{b})}{\textit{a}(\textit{x}+\textit{b})}$