Not really sure how the question is related to this material, but...
This appears to be Order of Operations: PEMDAS. When given any expression, you complete the operations in this order: Parentheses, Exponents, Multiplcation & Division (left to right), then Addition & Subtraction (left to right).
In this problem, you have Multiplication, Division and Addition, which are done in exactly that order.
So to solve, Multiply 3*1, Divide by 2, then add 2.