9/56-(7/15-5/12)×(3/14+1/2);

1)7/15-5/12=28/60-25/60=
3/60=1/20
2)3/14+1/2=3/14+7/14=
10/14=5/7
3)1/20·5/7=5/140=1/28
4)9/56-1/28=9/56-2/56=7/56=1/8=0,125