What is the name for the mathematical property involving addition or subtraction of fractions over a common denominator? For any number $x$ where $x\in\Bbb R$ and where $x\ne0$, what is the mathematical property which states that:
$${1-x^2\over x} = {1\over x} - {x^2\over x}$$

Just the computation rules for fractions:
$$
\frac{a - b}{c} = \frac{a + (-b)}{c}  \\
\frac{a + b}{c} = \frac{a}{c} + \frac{b}{c} \\
\frac{(-b)}{c} = -\frac{b}{c}
$$
for $a = 1$, $b = -x^2$ and $c = x \ne 0$.
