Choice C is the correct answer. The $2y$ terms are opposites, so we add the equations.

Step 1: Add the equations: $(6x + 2y) + (6x - 2y) = 20 + 16$$12x = 36$$x = 3$

Step 2: Substitute $x = 3$ into the first equation: $6(3) + 2y = 20$$18 + 2y = 20$$2y = 2$$y = 1$

Solution: $(3, 1)$

Verification: $6(3) - 2(1) = 18 - 2 = 16$ ✓

💡 Strategic Tip: Opposite coefficients make addition the fastest elimination method.

Choice A is incorrect because$6(2) + 2(4) = 12 + 8 = 20$ ✓, but $6(2) - 2(4) = 12 - 8 = 4 \ eq 16$.

Choice B is incorrect because$6(4) - 2(-2) = 24 + 4 = 28 \ eq 16$.

Choice D is incorrect because$6(5) + 2(-5) = 30 - 10 = 20$ ✓, but $6(5) - 2(-5) = 30 + 10 = 40 \ eq 16$.