2
3x7
18/21 = 6/7
no
21:6::7:2
299393809 and get a calculator its not that hard
well 0.6 is just like saying 6over 10
1.0000666666
There is no need to simplify this, it is only a sum. 21 + (10/2) - 18 = 8
21 hours 99 minutes
6/21 = 2/7 simplified
5*root(21^2) = 5*21 = 105