5} \atop {x<9}} \right.\\5<x<9\\\\6+7+8 = 21" alt="\left \{ {{x+1<2x-4} \atop {3x+1<2x+10}} \right.\\\\\left \{ {{x-2x<-4-1} \atop {3x-2x<10-1}} \right.\\\\\left \{ {{-x<-5} \atop {x<9}} \right.\\\\\left \{ {{x>5} \atop {x<9}} \right.\\5<x<9\\\\6+7+8 = 21" align="absmiddle" class="latex-formula">