Evaluate when a = 9, b = 6.

To evaluate a and b when a = 9 and b = 6, we simply substitute the given values into the expressions.

Therefore, when a = 9 and b = 6:

- a + b = 9 + 6 = 15
- a - b = 9 - 6 = 3
- a * b = 9 * 6 = 54
- a / b = 9 / 6 = 1.5

To evaluate the given expression with a = 9 and b = 6, we need to know the expression you would like to evaluate. Could you please provide the expression?

To evaluate an expression when given specific values for variables, substitute the given values into the expression and then perform the necessary calculations.

In this case, you have been given the values a = 9 and b = 6. However, you haven't provided an expression or equation to evaluate.

If you provide the expression or equation, I would be happy to guide you through the process of evaluating it.