1. **State the problem:** Simplify the expression $150 - 30h$. 2. **Identify the terms:** The expression consists of a constant term $150$ and a variable term $-30h$. 3. **Simplification:** Since the terms are unlike (one is a constant, the other contains variable $h$), they cannot be combined further. 4. **Final expression:** The simplified form remains $$150 - 30h$$. This expression represents a linear expression in $h$ with a constant term $150$ and a coefficient $-30$ for $h$.