Solve 3x = 9.

**The reasoning** To solve 3x = 9, we need to **isolate x** — get x alone on one side of the equation. The principle here is: **Whatever you do to one side, do to the other side.** Since x is being multiplied by 3, we do the opposite operation (division) to both sides: 3x = 9 Divide both sides by 3: 3x ÷ 3 = 9 ÷ 3 x = 3 Check it: 3(3) = 9 ✓ **Why the wrong options tempt you** **A) 1** — You might confuse this with solving 3 + x = 9 (which would give x = 6, not even option A!). Don't mix up addition and multiplication. **B) 2** — Maybe you thought "3 × 2 is close..." but maths demands exactness. 3 × 2 = 6, not 9. **D) 9** — This is just repeating the number you see in the equation. Remember: you're solving *for* x, not just picking a number from the question. **Quick takeaway** To solve ax = b, always divide both sides by the coefficient (the number stuck to x) — here, x = b/a = 9/3 = 3.