1) а. 4/7+(-11/14)=8/14-11/14=-3/14 б. -4/9-5/12=--16/36+15/36=-31/36
в. -14/25*20/21= -280/525=-8/15 г. 14/9 : (-16/15)= -210/144=-35/25=-1 11/24
2) -8/25*15/14-11/48:(-7/8)=-12/35-(-11/42)=-17/210
3) а. -8/19*13/15-8/19*2/15=-104/285-16/285=-8/19
б. 24/25-37/43-24/25*(37/43-15/16)=24/25-37/43-24/25*(-53/688)=107/1075-(-371/8600)=-1227/8600