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

Step 1: Add the equations: $(3x + 4y) + (3x - 4y) = 25 + 11$$6x = 36$$x = 6$

Step 2: Substitute $x = 6$ into the first equation: $3(6) + 4y = 25$$18 + 4y = 25$$4y = 7$$y = \frac{7}{4}$

Solution: $(6, \frac{7}{4})$

Verification: $3(6) - 4(\frac{7}{4}) = 18 - 7 = 11$ ✓

💡 Strategic Tip: Don't avoid fractional answers—they're common on the SAT.

Choice A is incorrect because$3(5) + 4(2.5) = 15 + 10 = 25$ ✓, but $3(5) - 4(2.5) = 15 - 10 = 5 \ eq 11$.

Choice B is incorrect because$3(7) + 4(1) = 21 + 4 = 25$ ✓, but $3(7) - 4(1) = 21 - 4 = 17 \ eq 11$.

Choice C is incorrect because$3(4) + 4(3.25) = 12 + 13 = 25$ ✓, but $3(4) - 13 = -1 \ eq 11$.