1. **State the problem:** Solve the equation $4=\frac{x}{5}$ for $x$. 2. **Formula and rule:** To solve for $x$ when it is divided by a number, multiply both sides of the equation by that number to isolate $x$. 3. **Multiply both sides by 5:** $$4=\frac{x}{5} \implies 4 \times 5 = \frac{x}{5} \times 5$$ 4. **Cancel the common factor 5 on the right side:** $$20 = \cancel{\frac{x}{5}} \times \cancel{5} = x$$ 5. **Final answer:** $$x = 20$$ This means that when $x$ is divided by 5, the result is 4, so $x$ must be 20.