Răspuns :
a+b+c=826
a+b=608
b+c=515
608+c=826
c=826-608
c=218
b+218=515
b=515-218
b=297
a+297=608
a=608-297
a=311
a+b=608
b+c=515
608+c=826
c=826-608
c=218
b+218=515
b=515-218
b=297
a+297=608
a=608-297
a=311
a+b+c=826. a=gaini. b=rate. c= gaste. a+b=608. Deci c= 826-608=218 gaste. b+c=826- 515=311gaini. a+b=608. Deci 311+b= 608. b=608-311=297rate. Verific. 311+218+297=826