a) 35-{12-[-14+(-2)]}.
= 35 - 12 + 14 + 2
= 35 + 14 - (12 - 2)
= 49 - 10
= 39
b) 160:{17+[9×5-(14+2048:256)]}.
= 160: {17 + [45 - (14 + 8)]}
= 160: {17 + [45 - 22)]}
= 160:{17 + 23}
= 160: 40 = 4
c) 20210-{225:[20×15-8×25]-25}.
= 1 - {225:[300 - 200] - 25}
= 1 - {225 : 100 - 25}
= 1 - {2,25 - 25}
= 1 + 25 - 2,25
= 23,75