Cho phan so 24/45. Hay Tim 1 so tu nhien sao cho khi lay mau.so cong voi so do va giu nguyen tu so ta duoc phan so moi bang phan so 1/5

cho phan so 13 phan 27,hay tim mot so tu nhien sao cho khi cong tu so voi so do va giu nguyen mau so ta duoc phan so moi co gia tri bang 7 phan 9,lam ntn vay binh

cho phan so 35/45 .tim mot so tu nhien sao cho khi dem tu so cong so do va giu nguyen mau so thi ta duoc phan so moi co gia tri bang 8/9 . so phai tim la

Cho phan so 17/35 tim mot so tu nhien sao cho khai tu so cong voi so do va giu nguyen mau so thi duoc phan so moi bang 5/7. Giup luon cach giai 

lay tu so cua phan so 49/75 tru di mot so tu nhien va giu nguyen mau so ta duoc phan so moi bang phan so 3/5 tim so tu nhien do

cho phan so 35 / 39 . Hay tim mot so tu nhien sao cho khi them so do vao mau so cua phan so da cho va giu nguyen tu so thi ta duoc phan so moi bang 5/6 . tim so tu nhien do

Tim mot so sao cho khi tu so cua phan so 13/36 cong voi so do va giu nguyen mau so thi duoc phan so moi bang 5/9.

a) viet so le nho nhat co 4 chu so biet so do lon hon 2000 va chia het cho 9

b) cho phan so 27/72 tim mot so tu nhien sao cho khi tu so cong voi so do va giu nguyen mau so thi duoc phan so moi bang 5/6

tim mot so sao cho khi cong tu so cua phan so 17/39 voi so do va giu nguyen mau so thi duoc phan so moi bang 2/3