1.a)x€{1,2,3,4,5,7}
71/16, 72/26, 73/36, 74/46, 75/56, 76/66, 77/76
b)x€{8,9}
78/86, 79/96
2.a)x€{6,7,8,9}
y€{0,1,2,3,4,5,6,7,8,9,}
68/50, 78/50, 88/50, 98/50....
b)x€{1,2,3,4,5}
y€{0,1,2,3,4,5,6,7,8,9}
18/50, 28/50, 38/50, 48/50, 58/59....(când este 58 mereu este supra 59)
/=supra
€{ }=aparține mulțimii