1. The problem is to evaluate the expression $3(-3)$. 2. This is a multiplication problem where a positive number is multiplied by a negative number. 3. The rule for multiplication with signs is: a positive times a negative equals a negative. 4. Multiply the absolute values: $3 \times 3 = 9$. 5. Apply the sign rule: since one number is negative, the result is negative. 6. Therefore, $3(-3) = -9$.