Question 23337
Actually, with order of operations, no parentheses are needed.

9 + 6 · 2 ÷ 3 - 1   <--multiply or divide first starting from left to right
9 + 12 ÷ 3 - 1   <--multiply or divide first starting from left to right
9 + 4 - 1   <--add or subtract starting from left to right
13 - 1   <--add or subtract starting from left to right
12