Order of precedence.
Parentheses then mult/division then add/subtraction, left to right.
6÷2(1+2) =
6/2*3 =
3*3 =
9
After solving the parentheses you go left to right in a simple div/mult issue, correct answer should be 9.
edit: Prolly makes it easier if you rewrite the problem as: 6÷2*(1+2) =
