Номер 1344.
1) 7,8-(-6,9) = 7,8+6,9 = 14,7;
2) -6,7-(-7,6) = -6,7+7,6 = 0,9;
3) -5,4-6,8 = -12,2;
4) -5,4/5-(-20,3/5) = -29/5+103/5 = 74/5 = 14,4/5;
5) -1,7/9-3,5/6 = -16/9-23/6 = -32/18-69/18 = -101/18;
6) 16/21-5,1/3 = 16/21-16/3 = 16/21-112/21 = -96/21.
Номер 1345.
1) -1,3/7-1/4 = -10/7-1/4 = -40/28-7/28 = -47/28;
2) 2,1/3-3,4/9 = 7/3-31/9 = 21/9-31/9 = -10/9;
3) -5,3/4-(-2,1/9) = -23/4+19/9 = -207/36+76/36 = -131/36;
4) -5,9-0 = -5,9;
5) 1-(-2,7) = 1+2,7 = 3,7;
6) 5-6,2/3 = -1,2/3.