Oh Boy, I'm representing our South African Education system here during apartheid years.

first thing i remember: "÷" is not the same as "/" dont ask me why, I cant bluddy remember, but whenever you see "÷" you must put the unknown in parentheses which changes the direction form left to right TO right to left.

"When dividing an [unknown] or [x] with "÷" put unknown in parenthesis and calculate first, then remove parenthesis"
"When dividing an [unknown] or [x] with "/" all follow the same rank, left to right.

thus

6 ÷ 2(1+2) is not the same as 6/2(1+2)

Using waht the OP gave us we have to use our parentheses on unknown and it looks like this:

is 6 divided by [2(1+2)]

6 divided by [2(3)]

6 divided by [6] now remove parenthesis

6/6
= 1

6/2(1+2) on the other hand is 9