467:
1) 4+(-10)=-6;
2) -7,5+(+3,5)=-4;
3) (-1,9)+(-5,1)= -7;
4) 7,8+(-2,8)=5;
5) -3,4+(-4,6)=-8;
6) -1,25+(-1,75)=-3.
477:
1) -5/12+3/8= -10/24+9/24= -1/24;
2) 7/15+(-2/5)= 7/15+(-6/15)= 1/15;
3) -1/8+3/5= -5/40+24/40= 19/40;
4) 5/8+(-1/4)= 5/8+(-2/8)= 3/8;
5) -3/5+2/2= -3/5+5/5= 2/5; (2/2=1=5/5);
6) 5/16+(-2/3)= 15/48+(-32/48)= -17/48.