255-55:{28-23:[13-6x(4-2xX)]}=244
55:{28-23:[13-6x(4-2xX)]}=255-244
55:{28-23:[13-6x(4-2xX)]}=11
28-23:[13-6x(4-2xX)]=55:11
28-23:[13-6x(4-2xX)]=5
23:[13-6x(4-2xX)]=28-5
23:[13-6x(4-2xX)]=23
13-6x(4-2xX)=23:23
13-6x(4-2xX)=1
6x(4-2xX)=13-1
6x(4-2xX)=12
4-2xX=12:6
4-2xX=2
2xX=4-2
2xX=2
X=2:2
X=1
Succes!!!! :)