I don’t know sorry but like how’s yoonbum doing? Also like wanna be friends?
1. Given (12+3)x, we can sum the numbers in the parenthesis to get 15x
2. Given 12x+3x, we can factor x to get (12+3)x and get the same as 1.
3. Given (12+3x)x, we have to distribute the x and we have 
4. This expression is already simplified.
Use PEMDAS method to execute operations in the following order:
- Parentheses
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
First equation:
12 + (38 - 18)2 = 12 + 20 × 2 = 52
Second equation:
(12)2 - 6(2 - 23) = 24 - 6(-21) = 24 + 126 = 150
Hope this helps.