D18: Consider the expression x + 5. Suppose that a child has gained 5 pounds within the last year. We could define x to be the child's weight last year (in pounds), and then x + 5 would be the child's current weight (in pounds). Describe a situation in which x represents a meaningful quantity and the expression given describes another meaningful quantity. Include units!

1. x + 3
2. x - 4
3. 3x
4. x/2