Answer:
The first one is -4 and the second one is 12. all you will need to do is change the + to a - then do for the first one which would be -7- -3= -4 so to check it you will need to use the + to check it so it will be -3+-4=-7. and for the second one you will need to do -11- -23=12 so to check it you will need to change the - to + so it will be set up as 12+ -23=-11.
Explanation: