А1. - 7/16 +7/12=-21/48+28/48=7/48 А2. 3 ⁴/7 ×(-28)=25/7 ×(-28/1)=-100 А3. - 7,8:(-0.06)=78/100×100/6=130 А4. 260-1/26=259 25/26 А5. (0,8×1,25-1,25):1/8+1,25(0,8-1)×8=-2 В1. 5м/сек = 0, 005км/сек В2. 0,26/1.3=2 1/5/x x=(13/10 ×11/5)/26/100=11