12+9•54

To solve this expression, we need to follow the order of operations: parentheses, exponents, multiplication and division (from left to right), and addition and subtraction (from left to right).

Given the expression: 12 + 9 * 54

First, we perform the multiplication operation: 9 * 54 = 486

Then, we add the result to 12: 12 + 486 = 498

Therefore, the result of the expression 12 + 9 * 54 is 498.