Как сделать дроби: 6 7/12-1 11/12=, 21 17/24-17 19/24=,2/3 + 1/4=,5/6+3/4=

79/12-23/12=56/12=4.8/12==4.2/3521/24-427/24=94/24=3.22/24=3.11/128/12+3/12=11/1210/12+9/12=19/12=1.7/12