5x{942-2x[.882-4x(79+5*x)]}=250
.{942-2x[882-4x(79+5*x)]}=250:5
{942-2x[.882-4x(79+5*x)]}=50
2x[882-4x(79+5*x)]=942-50
2x[882-4x(79+5*x)]=892
[882-4x(79+5*x)]=892:2
[.882-4x(79+5*x)]=446
4x(79+5*x)=882-446
4x(79+5*x)=436
79+5*x=436:4
79+5*x=109
5*x=109-79
5*x=30
x=30:5
x=6