Set 3: Linear Equations (Advanced)

Choice C is correct. Choice C is the correct answer. 1. Perimeter Formula: $P = 2(L + W)$ 2. Substitute: $42= 2((2 x + 3) + x)$ 3. Simplify: $42= 2(3 x + 3) \rightarrow 42 = 6 x + 6$ 4. Subtract 6: $36= 6 x$ 5. Divide by 6: $x = 6$ 6. Verify: $L=15, W=6$. $2(15+6) = 42$ ✓ Choice B is incorrect because it results from an error in the solution process. Choice D is incorrect because it results from an error in the solution process. Choice D is incorrect because it results from an error in the solution process.