cho day so:36,45,54
a) viet them 3 so hang thich hop vao day so tren
b) so hang thu 20 thuoc day so nao
c) so 3469 co thuoc day so tren khong?vi sao
giai chi tiet giup minh nhe
viet tiep 2 so hang vao day so sau :
5,6,8,10,...,...
Viet tiep 3 so hang vao moi day so sau
a, 2,7,22,67,...,...,...
b,1,2,3,6,12,...,...,...
tim so tu nhien co 2 chu so neu viet them chu so 0 xen giua chu so hang chuc va hang don vi cua so do ta duoc so moi gap 10 lan so can tim . neu viet them chu so 1 vao ben trai so vua nhan duoc thi so do gap len 3 lan . so can tim
tim so tu nhien co 2 chu so ,biet rang neu viet them chu so 0 xen giua chu so hang chuc va hang don vi cua so do ta duoc so moi gap 10 lan so can tim .Neu viet them chu so 1 vao ben trai so vua nhan duoc thi so do gap len 3 lan.
tim 1 so co ba chu so biet rang khi viet them chu so 0 xen giua chu so hang tram va hang chuc ta duoc so lon gap 7 lan so do [giai theo cach cau tao so va giai that day du
tim tong cua 2 so biet rang neu viet them vao so hang thu 1 3285 don vi va giu nguyen so hang thu 2 thi ta duoc tong moi la 45678
cho mot so co ba chu so neu viet them chu so 3 vao ben trai so do
cho mot so co 3 chu so neu viet them vao ben phai so do chu so ba thi so do tang them 6528 don vi tim so do