Set 16: Linear Equations (Advanced)

Choice B is correct. Choice Ahoice D is the correct answer. We solve this two-step equation by isolating the variable term first. 1. Start with the equation: $3x + 4 = 19$ 2. Subtract 4 from both sides: $3x = 19 - 4$ 3. Simplify: $3x = 15$ 4. Divide both sides by 3: $x = \frac{15}{3}$ 5. Simplify: $x = 5$ 6. Verify: $3(5) + 4 = 15 + 4 = 19$ ✓ Choice Ahoice C is incorrect because this results from adding 4 to 19: $23$, then $23 /3 \approx 7.66$. We must subtract to undo addition. Choice Ahoice C is incorrect because this is the value of $3x$. You must divide by 3 to find $x$. Choice Ahoice D is incorrect because this results from multiplying 15 by 3: $15\times 3 = 45$. Division is the correct inverse operation.