Choice D is the correct answer. The $4y$ terms are opposites, so we add the equations.

Step 1: Add the equations: $(x + 4y) + (x - 4y) = 22 + 6$$2x = 28$$x = 14$

Step 2: Substitute $x = 14$ into the first equation: $14 + 4y = 22$$4y = 8$$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 $10 - 4(3) = 10 - 12 = -2 \ eq 6$.

Choice B is incorrect because$16 - 4(1.5) = 16 - 6 = 10 \ eq 6$.

Choice C is incorrect because$12 + 4(2.5) = 12 + 10 = 22$ ✓, but $12 - 10 = 2 \ eq 6$.