The problem is to evaluate the expression $ac - 3$. However, the values of $a$ and $c$ are not provided. Therefore, we cannot evaluate the expression to a single numerical value. The problem might be incomplete. If $a$ and $c$ were provided, we would substitute their values into the expression $ac-3$ and simplify.

1. Problem Description

The problem is to evaluate the expression $ac - 3$. However, the values of $a$ and $c$ are not provided. Therefore, we cannot evaluate the expression to a single numerical value. The problem might be incomplete. If $a$ and $c$ were provided, we would substitute their values into the expression $ac-3$ and simplify.

2. Solution Steps

Since the values of the variables $a$ and $c$ are missing, we cannot find a numerical answer.

In general, if $a$ and $c$ were known, we would first multiply $a$ and $c$, and then subtract 3 from the result.

3. Final Answer

Without the values of $a$ and $c$, the expression $ac-3$ cannot be evaluated to a single number. The expression remains as $ac-3$.

Final Answer: $ac-3$