1)0
2)(5/12+3/8)*6/19=(5/4+1/8)*6/19=6/12=1/2*6/19=1/1*3/19=3/19
3)⅔*9/16-7/24*2/7=1/1*3/8-1/12*1/1=3/8-1/12=1/8*1/4=1/32
1)0
2)(5/12+3/8)*6/19=(5/4+1/8)*6/19=6/12=1/2*6/19=1/1*3/19=3/19
3)⅔*9/16-7/24*2/7=1/1*3/8-1/12*1/1=3/8-1/12=1/8*1/4=1/32