26 < a-b < 30
127 < a+b <130 adunam cele 2 inegalitati
153 < 2a < 160 |:2
76,5 < a < 80⇒ a∈{77,78,79}
1)26 < 77-b < 30 |-1 inmultim prima inegaliate cu -1
127 < 77+b < 130
-26 < -77 +b < -30
127 < 77 +b < 130 adunam cele 2 inegalitati
101 < 2b < 100 |:2
50,5 < b < 50 ⇒b∈{ 50,4; 50,3; 50,2; 50,1}
