Răspuns :
656+c=999
c=999-656
c=343
mergem la formula >>>b+c=504 >>>inlocuim b+343=504 >>>b=504-343=161
mergem la formula initiala >>>a+343+161=999 >>> a=999-343-161 >a=495
proba >>> 495+161+343 = 999
c=999-656
c=343
mergem la formula >>>b+c=504 >>>inlocuim b+343=504 >>>b=504-343=161
mergem la formula initiala >>>a+343+161=999 >>> a=999-343-161 >a=495
proba >>> 495+161+343 = 999