Decreases help needed

How-to Questions
1

So i knit this pattern : https://www.garnstudio.com/pattern.php?id=645&cid=17#add
I am really confused about the decreases. Right now i work on the right front piece, i did the 3 outermost sts bind off, and the next step is to shape the armhole like the back piece. I just dont understand this: “Knitting tips (for armhole):
All decs are made on right side rows.
Dec 1 st inside 3 edge sts knit in garter st as follows:
After 3 sts: Slip 1 as if to knit, K 1, psso.
Before 3 sts: K 2 tog.”

What does it mean dec 1 st INSIDE the 3 edge sts? And what the words “before” and “after” 3 sts mean.

I appreciate all of your help.

2

The armhole edge is going to continue with 3 garter edge sts. In order to maintain the 3 garter stitch edge you won’t be working the decreases at the edge but immediately before the armhole garter sts. In that sense, you are decreasing inside or within the main body of the right front rather than at the very edge.
Since this is the armhole edge on the right front (right front as you would wear the sweater) use the k2tog before the 3 sts as recommended in the notes.

3

Thank you very much!