a) [5/2-24/25×(25/16-3/8)]:6/5=
=[5/2-24/25×(25/16-6/16)]:6/5=
=(5/2-24/25×19/16):6/5=
=(5/2-3/25×19/2):6/5=
=(5/2-57/50):6/5=
=(125/50-57/50):6/5=
=68/50:6/5=
=34/25:6/5=
=34/25×5/6=17/15
b) [(5/14+2/7)×7/3+11/12]:5/2=
=[(5/14+4/14)×7/3+11/12]:5/2=
=(9/14×7/3+11/12):5/2=
=(3/2+11/12):5/2=
=(18/12+11/12):5/2=
=29/12:5/2=
=29/12×2/5=29/30
