Verified answer

1) -3,8+ 2 1/3= -19/5 + 7/3= -57/15 +35/15= -22/15

2) -22/15*(-1 7/8)= 22/15* 15/8= 22/8= 11/4

3) 4 1/6 : (-1 2/3)= 25/6 : (-5/3)= 25/6 * (-3/5)= - 5/2

4) 11/4- 5/2= 11/4- 10/4= 1/4

ответ 1/4 или 0,25