#### Answer

$\frac{25}{x}$

#### Work Step by Step

Let us call the other number $z$.
Since the product of the two numbers is $25$, and "product" indicates multiplication, we can write the following equation: $zx=25$
We must solve the equation for $z$, because we are looking for the "other number." To do so, we divide by $x$ on each side of the equation: $z=\frac{25}{x}$
Since the other number is equal to $z$, the other number is $\frac{25}{x}$