Decreasing each end of row?

need to decrease 3 stitches on back of sweater beginning and end of row for sleeves on sweater. Pattern is K2, P4. Tried by keeping pattern going but it didnt look very good. ??

You can bind off 3 sts at the biginning of the row and then turn and bind off 3sts at the beginning of the next row. You will sacrifice some of the pattern sts but just be sure to pick up the pattern after the bind offs. Look at the sts from the previous row and let that guide you for the current row.

can I just bind off by knitting - even though the 3rd thru 6 sts are purl?

You can BO knitwise, but the edge will look better if you purl the purl stitches. The BO is only the part where you lift the stitches over so they’re not on the needle, otherwise it’s like knitting another row of the pattern stitch.

Thank you very much for your help.

thanks so much - good advice!