3×4+2×9-{4+[45-5×(8-2×x)+23]:4}=14
12 + 18 -{4+[45-5×(8-2×x)+23] : 4} = 14
4+[45-5×(8-2×x)+23] : 4 = 30 - 14
4+[45-5×(8-2×x)+23] : 4 = 16
[45-5×(8-2×x)+23] : 4 = 16 - 4
[45-5×(8-2×x)+23] :4 = 12
45-5×(8-2×x)+23 = 12×4
45-5×(8-2×x) + 23 = 48
45 -5×(8-2×x) = 48-23
45-5×(8-2×x) = 25
5×(8-2×x) = 45-25
5×(8-2×x) = 20
8-2×x = 20:5
8-2×x = 4
2×x = 8-4
2×x = 4
x = 4 : 2
x = 2