1.-|-31/4|+(+7/2) =-31/4+14/4 =-17/4 2.|-4/5|+(+1/2) =4/5+1/2 =13/10; 3.-|-14|+|-12| =-14+12 =-2; 4.|-(-22/7)|+|-8/21| =22/7+8/21 =74/21;