2 . . +{[2 . - (5 . X + 4) . 5] : ( . 3 . 5)} = 453
2 . 25 . 6 +{[2 . 125 - (5 . x + 4) . 5] : (4 . 3 . 5)} = 453
300 + {[ 250 - (5 . x + 4) . 5] : 60} = 453
[ 250 - (5 . x + 4) . 5] : 60 = 453 - 300
[ 250 - (5 . x + 4) . 5] : 60 = 153
250 - (5 . x + 4) . 5 = 153 . 60
250 - (5 . x + 4) . 5 = 9180
250 - (5 . x + 4) = 9180 : 5
250 - (5 . x + 4) = 1836
5 . x + 4 = 250 - 1836
5 . x + 4 = -1586
5 . x = -1586 - 4
5 . x = -1590
x = -1590 : 5
x = -318