Răspuns :
a+b=550
a=b-40
b-40+b=550
2b-40=550
2b=550+40
2b=590
b=590:2
b=295
a=295-40
a=255
verific
255+295=550
a=b-40
b-40+b=550
2b-40=550
2b=550+40
2b=590
b=590:2
b=295
a=295-40
a=255
verific
255+295=550