1) 4032-250-2021 +4032-150+2021
=(4032+4032+2021)+(250+2021+150) =10085+2421 =12506
2) (300-452)-(700+300)-(-452+10)=300-452-700-300-452-10=(300-300)-(452-452)-(700-10)
= 0 - 0 - 690
= -690
-171+(-50+171)-(50-103)-(-3)=-171+(-50)+171-50+103-3=171-50+171-50+103-3=(171-171)-(50-50)+(103-3)=0-0+100=100