[ 3 9/16:( 2,75/(х:2/7-45)-7/24)+6,2]:12 2/3=1,2
3 9/16:( 2,75/(х*7/2-45)-7/24)+6,2=1,2*12 2/3
3 9/16:(2,75/(3,5х-45) - 7/24)+6,2=15,2
3 9/16:(2,75/(3,5х-45) - 7/24=15,2-6,2
3 9/16:(2,75/(3,5х-45) - 7/24=9
2,75/(3,5х-45) -7/24=3 9/16:9
2,75/(3,5х-45)=19/48+7/24
2,75/(3,5х-45)=11/16
3,5х-45=2,75:11/16
3,5х-45=4
3,5х=4+45
3,5х=49
х=49:3,5
х=14