105 - 49 + (72/9) i'm not sure what the answer so confused

72 divided by 9 equals 8 
105 - 49 + 8
105 - 49 equals 56
56 + 8 
56 + 8 equals 64
The answer is 64

To solve for this expression, use the acronym PEMDAS (Parentheses, Exponents, Multiplication and Division, Addition and Subtraction). To start, first perform (72/9) because division comes before addition and subtraction. This would simplify to 8 making your expression 105-49+8.
Then, perform 105-49 since while subtraction appears to come after addition, they are actually on the same level, meaning when you solve them in an expression, you perform them from left to right regardless if addition is first or not. This would then simplify to 56, making your expression 56+8. Finally, add 56 and 8 and you get your final answer which is 64. 

Ithink the answer is d. not sure but don’t answer it.

31 is prime. and it’s prime factorization is just 31.