Making armhole for sweater

#1

i am knitting a sweater. i am knitting the back, and have gotten to the part where i need to start shaping the armhole. the pattern reads" BO 2 sts beg next 2 rows" Do i BO 1 or 2 at each side?

#2

You have to bind off two stitches at the beginning of one row, work to the end. Then bind off two stitches at the beginning of the next row and work to the end.

You can’t bind off a stitch at the end of a row.