1)-7+(-8) =-7-8=-15
2)-0,38+(-0,74) =-0,38-0,74=-1,12
3)-1,8+(-0,34) =-1,8-0,34=-2,14
4)-4 6/7+(2 3/7)-4 6/7+2 3/7=-2 3/7
5)-5/6+(-7/8) =-5/6-7/8=(-5*6-7*4)/36=-58/36=-29/18=-1 11/18
6)-6 7/15+(-8 3/10)=-6 7/15-8 3/10=
=-6 14/30-8 9/30=-14 21/30=-14 7/10