1. **State the problem:** We are given that the sum of Al's age and Bob's age is 93. 2. **Write the equation:** Let Al's age be $A$ and Bob's age be $B$. The problem states: $$A + B = 93$$ 3. **Explain the formula:** This is a simple linear equation representing the sum of two variables. 4. **Interpretation:** Without additional information, we cannot find the exact ages of Al and Bob, only that their ages add up to 93. 5. **Example:** If Al is 50 years old, then Bob's age is: $$B = 93 - A = 93 - 50 = 43$$ 6. **Summary:** The sum of their ages is always 93, so for any age $A$ of Al, Bob's age is $93 - A$.