x12+3x4+56x+-=2652-xxx
x=?
2652=x12+3x4+56x+xxx
(x*100+1*10+2)+(3*100+x*10+4)+(5*100+6*10+x)+(x*100+x*10+x)=2652
(100x+10+2)+(300+10x+4)+(500+60+x)+(100x+10x+x)=2652
(100x+12)+(304+10x)+(560+x)+111x=2652
(100x+10x+x+111x)+(12+304+560)=2652
(110x+112x)+(316+560)=2652
222x+876=2652
222x=2652-876
222x=1776
x=1776:222
x=8
verificare
812+384+568=2652-888
1196+568=1764
1764=1764