You use pemdas to figure this out, so you do whats in the parentheses first, 2x-6, but instead you do 2(4)-6 and when your solving stuff in the parentheses you apply pemdas again to figure out what to do, so you multiply 2x4 first bcz m is before s, and then you do 8-6 bcz there's nothing else to do in the parentheses. now that your done with the parantheses you currently have 3x3 +2(2). now you dont have p or e but you do have m and when you have multiple instances of multiplication you do it left from right, so you do 3x3 first and get 9 and then you do 2x2 and get 4. now you have 9+4 and since you have nothing else to do you add and you get 13.
