Real Multiplication Distributes over Addition

Theorem
The operation of multiplication on the set of real numbers $\R$ is distributive over the operation of addition:
 * $\forall x, y, z \in \R:$
 * $x \times \paren {y + z} = x \times y + x \times z$
 * $\paren {y + z} \times x = y \times x + z \times x$