What Lionel said.
The "rule of operator sequence is BODMAS", (Brackets, Of, Division, Multiplication, Addition then Subtraction).
So I'd agree 3÷1/3 = 9, but then the Addition of 1 makes that 10 and that subtracted from 9 leaves us in negative territory at -1.
However, the "AS" (Addition and Subtraction) order is over-ridden by the "Left to Right" priority, therefore it reads as
9-9+1= 1