Question 871639
-3 < 3x < 12
-1 < x < 4 
shade area between the two vertical Lines
{{{drawing(300,300,   -6, 6, -6, 6, grid(1), blue(line(4,6,4,-6)) ,blue(line(-1,6,-1,-6)) ,
graph( 300, 300, -6, 6, -6, 6) )}}}