37+7+A=52 unde a=52-(37+7)=52-44=8
51+29+a=95 unde a=95-80=15
22+a+30=80 unde a=80-52=28
a+18+46=71 unde a=71-64=7
62-4-a=37 unde a=62-4-37=21
43-15-a=9 unde a=43-15-9=37
87-78-a=3 unde a=87-78-3=12
70-44-a=19 unde a=70-44-19=7
a-13-23=34 unde a=13+23+34=70
a-9-15=41 unde a=9+16+41=66
a-34-16=10 unde a=34+16+10=60
a-72-5=7 unde a=72+5+7=84
