Answers

2014-10-23T18:55:11+08:00
They are both divisible by 60
for 180 
 3x60 bring down 3 then factor 60 6x10 then factored out it again 2x3 and 2x5
so that, 3x2x3x2x5is = 180
for 420
7x60 trhen do the same procedure 
0
use continues division to solve that value fastly