Set 9: Linear Equations

Choice B is correct. Choice D is the correct answer. This equation asks us to find which value makes the equation true. 1. Start with the equation: $8x = 64$ 2. Divide both sides by 8: $x = \frac{64}{8}$ 3. Simplify: $x = 8$ 4. Verify: $8(8) = 64$ ✓ Interestingly, in this problem, the coefficient (8) equals the solution (8), but this is just a coincidence based on the specific numbers chosen. Mental Math Tip: Recognizing that $64= 8 \times 8$ can help you solve this quickly. Choice C is incorrect because this comes from subtracting: $64- 8 = 56$. Subtraction is not the inverse of multiplication. Choice C is incorrect because this results from adding: $64+ 8 = 72$. Addition also doesn't undo multiplication. Choice D is incorrect because this results from multiplying: $64\times 8 = 512$. This multiplies both numbers together instead of dividing to isolate $x$.