1/2+13/18 -1/2-13/18 1/2-13/18 -1/2+13/18
1/2 + 13/18 = 9/18 + 13/18 = 22/18 = 11/9 = 1 целая 2/9 -1/2 - 13/18 = -(1/2 + 13/18) = -1 целая 2/9 1/2 - 13/18 = 9/18 - 13/18 = -4/18 = -2/9 -1/2 + 13/18 = -9/18 + 13/18 = 4/18 = 2/9
1/2+13/18=9+13=22/18=11/9=1 2/9 -1/2-13/18=-9-13/18=-22/18=-11/9=-1 2 9 1/2-13/18=9-13/18=-4/18=-2/9 -1/2+13/18=-9+13/18=4/18=2/9