Choice Bhoice D is the correct answer. To solve this multiplication equation, we divide both sides by the coefficient.

1. Start with the equation: $15x = 75$
2. Divide both sides by 15: $x = \frac{75}{15}$
3. Simplify: $x = 5$
4. Verify: $15(5) = 75$ ✓

💡 Shortcut: If you know your multiplication facts, $15 \times 5 = 75$ is recognizable, so $x = 5$ immediately.

Choice Bhoice A is incorrect because this results from adding: $75 + 15 = 90$. Addition is not the inverse of multiplication.

Choice Bhoice C is incorrect because this comes from subtracting: $75 - 15 = 60$. Subtraction doesn't solve multiplication equations.

Choice Bhoice D is incorrect because this results from multiplying: $75 \times 15 = 1125$. This multiplies again instead of dividing to isolate $x$.