Вычислите значение выражения: 1) 2/15 + (-3/10); 5) -5 7/8 +

1) 2/15 + (-3/10)=(4+(-9))/30=-50/30=-1/6;
2) - 2/3 + 13/15=(-10+13)/15=3/15=1/5;
3) 13/16 + (-9/32)=(26+(-9))/32=17/32;
4) - 4 5/9 + (- 7 1/6)=-11 + (-13/18)=-11 13/18;
5) -5 7/8 + (-6 3/10)=-11 + ((-35)+(-12))/40=-11 + (-47/40)=-12 7/40;
6) -5 13/18 + 12 11/12=7 11/12 - 13/18=7 + (33-26)/36=7 7/36;
7) -13 + 7 3/16=-6 + 3/16=-5 13/16;
8) - 2 3/8 + (- 1 5/9)=-3 + ((-27)+(-40))/72=-3 + (-67/72)=-3 67/72;
9) -8 + 4 5/22=-4 + 5/22=-3 17/22;
10) -2 9/20 + 5 7/30=3 7/30 - 9/20=3+(14-27)/60=3+(-13/60)=2 47/60;
11) - 5 1/4 + 1 3/8=-4 1/4 + 3/8=-4 + (-2+3)/8=-4 + 1/8=-3 7/8;
12) 4 3/7 + (-8 9/14)=- 4 9/14 + 3/7=- 4 9/14 + 6/14=-4 3/14.