Choice Choice A is the correct answer. This is a one-step multiplication equation requiring division to solve.

1. Start with the equation: $5x = 45$
2. Identify the coefficient: The variable is multiplied by 5
3. Divide both sides by 5: $x = \frac{45}{5}$
4. Simplify: $x = 9$
5. Verify: $5(9) = 45$ ✓

💡 Pattern Recognition: In equations of the form $ax = b$, the solution is always $x = \frac{b}{a}$.

Choice Choice C is incorrect because this results from subtracting 5 from 45: $45 - 5 = 40$. Subtraction is not the correct inverse operation for multiplication.

Choice Choice B is incorrect because this comes from adding: $45 + 5 = 50$. Addition also doesn't undo multiplication.

Choice Choice C is incorrect because this results from multiplying 45 by 5 instead of dividing: $45 \times 5 = 225$. This compounds the multiplication rather than undoing it.