a)b:8=312
b=312x8
b=2496
b)86:c=2
c=86:2
b=43
c)x:9=13 rest 5
x=13x9+5
x=117+5
x=122
2)58:2=29
29x2=58
46:3=15 rest 1
15x3+1=
45+1=46
108:3=36
36x3=108
209:4=52 rest 1
52x4+1=
208+1=209
420:5=84
84X5=420
726:8=90 REST 6
90X8+6=
720+6=726
824:6=137 REST 2
137X6+2=
822+2=824
957:7=136 REST5
136X7+5=
952+5=957