Easy, just write out the multiple of the numbers.
4: 4,8,12,16,20,24,28,32,36,40,44,48,52,56,60
7: 7,14,21,28,35,42,49,56,63,70
Etc.
But a few common multiples:
28,56,84,112,140
These are the first 5 common multiples of 4 and 7.
408 round to the nearest tenth: 410
Yo sup??
Let the length of river D be x
then the lenght of river C will be 200+x
but,
lenght of river C+lenght of river D=5580
x+x+200=5580
2x=5380
x=2690
Therefore lenght of river D is 2690 and that of C is 2890
Hope this helps
