Set 11: Linear Equations (Advanced)

Choice D is correct. Choice 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 A is incorrect because this results from adding: $75+ 15 = 90$. Addition is not the inverse of multiplication. Choice C is incorrect because this comes from subtracting: $75- 15 = 60$. Subtraction doesn't solve multiplication equations. Choice D is incorrect because this results from multiplying: $75\times 15 = 1125$. This multiplies again instead of dividing to isolate $x$.