[tex]\displaystyle\bf\\Cautam~numere~de~forma~~\overline{abba}~~in~care\!:\\a\neq b\\\overline{ab}~si~\overline{ba}~sunt~numere~prime.\\\\Rezolvare\!:\\\\Numerele~prime~cu~2~cifre~sunt\!:\\11; 13; 17; 19; 23; 29; 31; 37; 41; 43; 47; 53; 59; 61; 67; 71; 73; 79; 83; 89; 97\\\\Dintre~acestea~cele~care~indeplinesc~conditiile~date,~sunt\!:\\13~si~31\\17~si~71\\37~si~73\\79~si~97\\\\Solutiile~posibile~pentru~~\overline{abba}~~sunt:\!\\\\1331;~3113;~1771;~7117;~3773;~7337;~7997;~9779\\\\Total~8~numere[/tex]