## Prealgebra (7th Edition)

When fractions are equivalent, the cross products are equivalent. The term cross product is derived from the X shape of the numbers being multiplied. $\frac{a}{b}=\frac{x}{y}$ $\frac{a}{b}\nearrow\!\!\!\!\!\!\searrow\frac{x}{y}$ $\Rightarrow ay=bx$