1) -3 8/10+2 1/3= -3 4/5+2 1/3= -19/5+7/3= -57/15+35/15= -22/15 = -1 7/15
2) -22/15*(-1 7/8)= -22/15* (-15/8)= 22/8= 11/4= 2 3/4
3) 4 1/6: (-1 2/3)= 25/6 : (- 5/3)= 25/6 * (-3/5)= -5/2 = -2 1/2
4) 11/4+ (-5/2)= 11/4 - 5/2= 11/4 -10/4= 1/4 = 0,25.
Ответ: 1/4 или 0,25