What is a if 2a = 18?

What is a if 2a = 18?

• A. 6
• B. 18
• C. 9
• D. 3

Answer: (C)

Solving a simple equation by undoing multiplication. If 2a = 18, isolate a by dividing both sides by 2, since division undoes multiplication. This gives a = 18 ÷ 2 = 9. Check: 2 × 9 = 18, which matches the given equation. Other values don’t fit because they produce different results on the left: 2×6 = 12, 2×18 = 36, and 2×3 = 6. So 9 is the value that satisfies the equation.

Solving a simple equation by undoing multiplication. If 2a = 18, isolate a by dividing both sides by 2, since division undoes multiplication. This gives a = 18 ÷ 2 = 9. Check: 2 × 9 = 18, which matches the given equation. Other values don’t fit because they produce different results on the left: 2×6 = 12, 2×18 = 36, and 2×3 = 6. So 9 is the value that satisfies the equation.