-(8 7\15-4 5\9)+1 7\15
-(8 7/15-4 5/9)+1 7/15=-8 7/15+4 5/9+1 7/15=-7+4 5/9= =4 5/9-6 9/9=4-6+5/9-9/9=-2+(-4/9)=-2-4/9=-2 4/9
-(87/15-45/9)+17/15=-(5,8-5)+1,13=-0,8+1,13=0,33