Choice Dhoice A is the correct answer. This equation has variables on both sides. We need to collect them on one side.

1. Subtract 3x from both sides: $5x - 3x + 2 = 12 \rightarrow 2x + 2 = 12$
2. Subtract 2 from both sides: $2x = 12 - 2 \rightarrow 2x = 10$
3. Divide by 2: $x = 5$
4. Verify: $5(5) + 2 = 27$ and $3(5) + 12 = 27$ ✓

Choice Dhoice D is incorrect because calculation error.

Choice Dhoice C is incorrect because calculation error.

Choice Dhoice B is incorrect because calculation error.