Răspuns :
a+b+c=113
a+b=56
b=c:3
56+c=113
c=57
b=57:3=19
a+19+57=113
a+76=113
a=37
verific 37+19+57=113
a+b=56
b=c:3
56+c=113
c=57
b=57:3=19
a+19+57=113
a+76=113
a=37
verific 37+19+57=113