Set 2: Systems of Equations (Advanced)

Choice D is correct. Choice D is the correct answer. The $4y$ terms are opposites, so we add the equations. Step 1: Add the equations: (x + 4 y) + (x - 4 y) = 22 + 6$2x = 28$x = 14 Step 2: Substitute $x = 14$ into the first equation: $$$14+ 4 y = 224y = 8$y = 2 Solution: $(14, 2)$ Verification: $14- 4(2) = 14 - 8 = 6$ ✓ Strategic Tip: When terms are opposites, adding is the most direct path to elimination. Choice A is incorrect because $10+ 4(3) = 10 + 12 = 22$ ✓, but $10- 4(3) = 10 - 12 = -2 \neq 6$. Choice B is incorrect because $16- 4(1.5) = 16 - 6 = 10 \neq 6$. Choice C is incorrect because $12+ 4(2.5) = 12 + 10 = 22$ ✓, but $12- 10 = 2 \neq 6$.