\(\Rightarrow x-1\in B\left(60\right)=\left\{0;60;120;240;360;...\right\}\\ \Rightarrow x\in\left\{1;61;121;241\right\}\left(x< 250\right)\)
Ta có :
BC(4,5,6) = 60 , 120 , 180 , ...
=> x - 1 = 60 , 120 , 180 , 240 , ...
=> x = 61 , 121 , 181 , 241 , ...
Mà x < 250 => x = 61 , 121 , 181 , 241