Choice Choice B is the correct answer. We isolate the variable term first by adding 7.

1. Start with the equation: $3x - 7 = 14$
2. Add 7 to both sides: $3x = 14 + 7$
3. Simplify: $3x = 21$
4. Divide both sides by 3: $x = \frac{21}{3}$
5. Simplify: $x = 7$
6. Verify: $3(7) - 7 = 21 - 7 = 14$ ✓

💡 Key Step: Always isolate the term with the variable (here, $3x$) before trying to isolate the variable itself ($x$).

Choice Choice D is incorrect because this results from subtracting 7 from 14: $14 - 7 = 7$, then $7/3 \approx 2.33$. We must add to undo subtraction.

Choice Choice B is incorrect because this is the value of $3x$, not $x$. Students often stop halfway through the problem.

Choice Choice C is incorrect because this results from multiplying 21 by 3 instead of dividing: $21 \times 3 = 63$.