Răspuns:
a+(11000-1000)=217000
a+10000=217000
a=217000-10000
a=207000
(285402-53100)-a=112101
232300-a=112101
a=232300-112101
a=120199
a-(111904+111005)=123000
a-899=123000
a=123000+899
a=123899
(240104+510250)-a=340144
750354-a=340144
a=750354-340144
a=410210