Final answer:
To represent three times as much as an unknown number, use the expression 3x.
Step-by-step explanation:
To represent three times as much as an unknown number, we can use the expression 3x, where x represents the unknown number. This means that if the unknown number is 5, then three times as much as that would be 3 * 5 = 15. Similarly, if the unknown number is 10, then three times as much as that would be 3 * 10 = 30.
Learn more about Representing unknown numbers