How do I remove cell contents if it exists in another cell?

For example:

Cell A1 has:
Peter is walking his dog
Cell B1 has:
walking his dog

preferably how can I remove the "walking his dog" from cell A1

or to create a new cell which contains "Peter is"

Hi,

You can do this:

Excel 2016 (Windows) 64 bit

	A	B	C
1	Peter is walking his dog	walking his dog	Peter is
2	Paul is feeding his cat	playing with his cat
3	Paul is playing with his cat	Paul is playing	with his cat

Sheet: Sheet41

Excel 2016 (Windows) 64 bit

	C
1	=IF(ISNUMBER(SEARCH(B1,A1)),TRIM(SUBSTITUTE(A1,B1,"")),"")

Sheet: Sheet41

Formula copied down.

Same question asked here: https://www.excelforum.com/excel-for...ntains-it.html