2(17-2x)-5 [tex] \geq [/tex] -31-x
34-4x-5 [tex] \geq [/tex] -31 -x
29-4x [tex] \geq [/tex] -31-x
29+31 [tex] \geq [/tex] -x+4x
60 [tex] \geq [/tex] 3x | /3
20[tex] \geq [/tex] x => A ={1,2,3,4,5 .... 20}
numere prime: 2,3,5,7,11, 13 ,17, 19
p=8/20 => p=2/5
