-50 to -51; 49 to 50; -48 to -49; 48 to 49; 50 to 51
I just add one
A. would your best answer....hope this helps.
1/40+1/50=1/n
5/200+4/200=1/n
9/200=1/n
9n=200
n=200/9 minutes for both of them to prepare the field
☺☺☺☺
Examples of inverse operations are addition and subtraction or multiplication and division.