Solve: 5x = 35.

**The reasoning** This is a simple linear equation. To find x, we need to isolate it on one side. We have: 5x = 35 Divide both sides by 5: x = 35 ÷ 5 = 7 **Principle: Inverse operations** — Whatever you do to one side of an equation, do to the other. Since x is multiplied by 5, we divide by 5 to "undo" it. **Why the wrong options tempt you** - **Option A (5):** You might confuse the coefficient (the number multiplying x) with the answer itself. Don't just pick numbers you see! - **Option B (6):** This could come from careless mental math — maybe rushing and thinking 5 × 6 = 30, then adjusting wrongly. - **Option D (8):** Another mental math slip, perhaps confusing it with 40 ÷ 5. The trap is **not verifying your answer**. Always check: Does 5 × 7 = 35? Yes! **Quick takeaway** To solve ax = b, divide both sides by a to get x = b/a — then always substitute back to confirm your answer works.