=(-5/6)÷[-(3+ 1/6)]÷{ 1/24×[-( 1+ 1/4)]}- 1/4÷ 1/4

=(-5/6)÷(- 19/3)÷[ 1/24×(-5/4)]- 1

=5/6×3/ 19÷(-5/96)- 1

=-5/6×3/ 19×96/5- 1

=-48/ 19- 1

=-67/ 19

I hope I can help you and wish you progress in your study.