Choice A is the correct answer. Since $x = 3y + 1$ is already isolated, substitute directly.

Step 1: Substitute into second equation: $2(3y + 1) + 5y = 13$$6y + 2 + 5y = 13$$11y = 11$$y = 1$

• First: $4 = 3(1) + 1 = 4$ ✓
• Second: $2(4) + 5(1) = 8 + 5 = 13$ ✓

Choice B is incorrect because$2(4) + 5(1) = 13 \ eq 24$.

Choice C is incorrect because$2(10) + 5(3) = 35 \ eq 24$.

**Choice D is incorrect.