R\mathbb{R}R
{x∈R:x>−ab}\left\{x \in \mathbb{R}: x>-\frac{a}{b}\right\}{x∈R:x>−ba}
R−{0}\mathbb{R}-\{0\}R−{0}
{x∈R:x>−ba}\left\{x \in \mathbb{R}: x>-\frac{b}{a}\right\}{x∈R:x>−ab}