Răspuns :
a+b = 999
a-b =1
a=b+1
b+1 +b = 999
2b +1 =999
2b = 999-1
2b = 998
b=998:2
b= 499
a = 499+1 = 500
500 + 499 = 999
500 - 499 = 1
a-b =1
a=b+1
b+1 +b = 999
2b +1 =999
2b = 999-1
2b = 998
b=998:2
b= 499
a = 499+1 = 500
500 + 499 = 999
500 - 499 = 1
a+b=999
a-b=1 => a=b+1
b+1+b=999
2b+1=999
2b=999-1
2b=998
b=998:2=499
a=499+1
a=500
a-b=1 => a=b+1
b+1+b=999
2b+1=999
2b=999-1
2b=998
b=998:2=499
a=499+1
a=500