1. 54200 - 49 * 76 - (24,792 + 5874) : (207 - 169) + 705 * 108 : 30 = 54200 - 49 * 76 - 5898,792 : 38 + 705 * 108 : 30 = 54200 - 3724 - 155,23136842 + 2538 = 50476 - 155,23136842 + 2538 = 50320,768631 + 2538 = 52858,768631
2.
200 - (48 : t) * 45 = 20
(48 : t) * 45 = 200 - 20
(48 : t) * 45 = 180
(48 : t) = 180 : 45
(48 : t) = 4
t = 48 : 4
t = 12