<PRE><B>Question 348548</B>
133 to base four : 
 
3(10)=3(4)
 
30(10)=3*10(10)=3*22(4)=3*2(4)+3*20(4)=12(4)+120(4)=132(4)
 
100(10)=10(10)+3*30(10)=22(4)+3*132(4)=22(4)+3*2(4)+3*30(4)+3*100(4)
=22(4)+12(4)+210(4)+300(4)
=32(4)+2(4)+1110(4)=100(4)+1110(4)=1210(4)
 
hence 133(10)=3(4)+132(4)+1210(4)=201(4)+1210(4)=2011(4)
 
Verif : 1+4+2*64=5+2*64=128+5=133

---------
  

5881 to base nine (default : from base 10)

81(10)=9*9=100(9)
 
800(10)=8*100(10)=8*10(10)*10(10)=8*11(9)*11(9)=8*[11(9)+10(9)*11(9)]=8*[11(9)+110(9)]=8*121(9)=1078(9)
 
5000(10)=5*121(9)*10(10)=5*121(9)*11(9)=5*[121(9)+1210(9)]=5*1331(9)
=6765(9)
 
100(9)+1078(9)+6765(9)=1178(9)+6765(9)=8054(9)
 
Verif : 4+5*9+8*9^3=49+8*729=49+5832=5881</PRE>