2a/ 2x - 3 = 16 => 2x - 3 = 24 => x - 3 = 4 => x = 7
b/ {x2 - [82 - (52 - 8.3)3 - 7.9]3 - 4.12}3 = 1
=> x2 - [82 - (52 - 8.3)3 - 7.9]3 - 4.12 = 1
=> x2 - [64 - (25 - 8.3)3 - 7.9]3 = 1 + 4.12 = 49
=> x2 - (64 - 13 - 63)3 = 49
=> x2 - 0 = 49
=> x2 = 49
=> x = 7